The plan of an office block for six officers A, B, C, D, E and F is as follows: Both B and C occupy offices to the right of the corridor (as one enters the office block) and A occupies on the left of the corridor. E and F occupy offices on opposite sides of the corridor but their offices do not face each other. The offices of C and D face each other. E does not have a corner office. F's office is further down the corridor than A's, but on the same side. Who is/are F's immediate neighbour/neighbours?

Let's deduce the office layout step-by-step:

1. Sides of the corridor:

   • From "B and C occupy offices to the right... and A occupies on the left...", we have: Left: A | Right: B, C.
   • From "C and D face each other...", since C is on the Right, D must be on the Left. So: Left: A, D | Right: B, C.
   • From "F's office is further down the corridor than A's, but on the same side...", F is on the Left side with A. So: Left: A, D, F | Right: B, C.
   • From "E and F occupy offices on opposite sides...", since F is on the Left, E must be on the Right. So: Left: A, D, F (3 officers) | Right: B, C, E (3 officers). This implies a block with 3 offices on each side of the corridor.

2. Placing E:

   • "E does not have a corner office." In a block with 3 offices per side, the middle office is the only non-corner office. Therefore, E must be in the middle office on the Right side (let's call it Right-2).

3. Placing C and D:

   • "The offices of C and D face each other." C is on the Right, D is on the Left. Since E is in Right-2, C cannot be in Right-2. So C must be in Right-1 or Right-3.
   • Case 1: C is in Right-1. Then D is in Left-1.
     • Right Side: C (Office 1), E (Office 2), B (Office 3 - remaining officer).
     • Left Side: D (Office 1). A and F are remaining for Left-2 and Left-3.
   • Case 2: C is in Right-3. Then D is in Left-3.
     • Right Side: B (Office 1 - remaining), E (Office 2), C (Office 3).
     • Left Side: D (Office 3). A and F are remaining for Left-1 and Left-2.

4. Placing A and F:

   • "F's office is further down the corridor than A's, but on the same side." This means A is closer to the entrance than F on the Left side.

5. Testing Case 1 (C in Right-1, D in Left-1):

   • Left Side: D (Office 1). A and F must be in Left-2 and Left-3, with A before F. So, A (Office 2), F (Office 3).
   • Right Side: C (Office 1), E (Office 2), B (Office 3).
   • Check all conditions:
     • A(L), B(R), C(R) - OK.
     • C(R-1) and D(L-1) face each other - OK.
     • E(R-2) is not a corner office - OK.
     • F(L-3) is further down than A(L-2) - OK.
     • "E and F occupy offices on opposite sides... but their offices do not face each other." E is in Right-2, F is in Left-3. E faces A (Left-2), F faces B (Right-3). They do not face each other. This layout is VALID.

6. Testing Case 2 (C in Right-3, D in Left-3):

   • Left Side: D (Office 3). A and F must be in Left-1 and Left-2, with A before F. So, A (Office 1), F (Office 2).
   • Right Side: B (Office 1), E (Office 2), C (Office 3).
   • Check condition: "E and F occupy offices on opposite sides... but their offices do not face each other." E is in Right-2, F is in Left-2. They are on opposite sides and DO face each other. This violates the condition. This layout is INVALID.

7. The Final Valid Layout:

   • Left Side: D (Office 1), A (Office 2), F (Office 3)
   • Right Side: C (Office 1), E (Office 2), B (Office 3)

8. Identify F's immediate neighbour(s):

   • F is in Left Office 3. In a linear arrangement of offices along a corridor, "immediate neighbour" typically refers to offices directly adjacent on the same side.
   • F's office (Left-3) is adjacent to A's office (Left-2) on the same side.
   • F's office (Left-3) is opposite B's office (Right-3). However, if the question implies "immediate neighbour" strictly on the same side (sharing a wall), then A is the only one. Given the options, this interpretation is intended.

Therefore, F's immediate neighbour is A.

The final answer is A