Consider the sequence AB_CC_A_BCCC_BBC_C that follows a certain pattern. Which one of the following completes the sequence?

The given sequence is: AB_CC_A_BCCC_BBC_C

First, let's count the total number of positions (including blanks) in the sequence. A (1) B (2) _ (3) C (4) C (5) _ (6) A (7) _ (8) B (9) C (10) C (11) C (12) _ (13) B (14) B (15) C (16) _ (17) C (18) There are 18 positions in total, with 5 blanks.

Now, let's try filling the blanks with the letters from Option C: B, C, B, A, C. The blanks are at positions 3, 6, 8, 13, and 17.

1. Fill the 1st blank (position 3) with 'B'.
2. Fill the 2nd blank (position 6) with 'C'.
3. Fill the 3rd blank (position 8) with 'B'.
4. Fill the 4th blank (position 13) with 'A'.
5. Fill the 5th blank (position 17) with 'C'.

The sequence becomes: A B (B) C C (C) A (B) B C C C (A) B B C (C) C

Let's write out the complete sequence after filling the blanks: A B B C C C A B B C C C A B B C C C

Now, observe the pattern in this completed sequence. It can be clearly divided into three identical blocks: (A B B C C C) (A B B C C C) (A B B C C C)

Each block is "ABBC CC", which is 6 characters long. Since there are three such blocks, the total length is 3 * 6 = 18 characters, matching the total positions in the sequence. This indicates a consistent repeating pattern.

Let's briefly check why other options are incorrect: If we fill with Option A (B, C, B, C, A): A B B C C C A B B C C C C B B C A C - No clear repeating pattern. If we fill with Option B (A, C, B, C, A): A B A C C C A B B C C C C B B C A C - No clear repeating pattern. If we fill with Option D (C, B, B, A, C): A B C C C B A B B C C C A B B C C C - No clear repeating pattern.

Thus, Option C is the only one that completes the sequence to form a logical and consistent repeating pattern.

The final answer is C