Why is rainfall uncertainty important while studying India's monsoon climate?

Correct answer: Because delay or deficiency of monsoon affects water and farming

The direct answer is B: delay or deficiency of the monsoon affects water and farming. India depends greatly on seasonal monsoon rain. Rainfall is uncertain because its arrival, duration and amount can vary from year to year and from one region to another. Reasoning step by step: if the monsoon arrives late, sowing may be delayed; if rainfall is deficient, crops may not receive enough water; reservoirs, rivers and groundwater may also receive less water; consequently farming, drinking-water supply and planning are affected. Option B is correct because it states this practical connection. Option A is false: rainfall strongly affects agriculture. Option C is false because rainfall is not equal everywhere or every year. Option D is false and irrelevant: the monsoon is not a phenomenon that gives only winter; in India it is mainly associated with seasonal summer rainfall, though monsoon systems have different branches and seasons. Memory cue: uncertain timing plus uncertain amount means uncertain farm and water planning.