Concept:
- The three cropping seasons of India already sort the crops by climate, so placing each option in its season answers the question.
- Kharif crops need heat and moisture, rabi crops need cool and dry weather.
Step 1: Sort the four options by season.
Peas, wheat and gram are all rabi crops, sown between October and December and harvested between April and June. Sugarcane is grown in the hot months and takes almost a year in the field.
Step 2: Match the season with the climate in the question.
Hot and humid air describes the monsoon period, not the winter. Three of the four options therefore fall out at once, since they are winter crops.
Step 3: Confirm with the growing conditions of the surviving crop.
Sugarcane needs a temperature of $21^\circ$C to $27^\circ$C and 75 cm to 100 cm of annual rainfall, which is exactly a hot and humid setting.
Step 4: Add a supporting fact.
It is the main source of sugar, gur, khandsari and molasses, and India stands second in the world in its production after Brazil, chiefly because so much of the country has the warm moist climate it needs.
Final Answer: (A) Sugarcane