Which one of the following is the correct sequence of the given Indian Cities in the decreasing order of their normal annual rainfall?

The correct sequence is C because of the geographical distribution of the monsoon in India.

Kochi is located on the windward side of the Western Ghats and receives the highest rainfall among the four due to the direct impact of the South West Monsoon.

Kolkata follows Kochi as it is located in the coastal region of West Bengal and receives heavy rainfall from the Bay of Bengal branch of the monsoon.

Patna is situated further inland in the middle Ganga plain. Since the moisture content of the monsoon winds decreases as they move from east to west along the Himalayan foothills, Patna receives less rainfall than Kolkata.

Delhi is located furthest inland in the semi arid region of Northwest India. By the time the monsoon winds reach Delhi, they have lost most of their moisture, resulting in the lowest annual rainfall among the given cities.

Therefore, the decreasing order is Kochi, Kolkata, Patna, and Delhi.