The crop is subtropical in nature. A hard frost is injurious to it. It requires at least 210 frost-free days and 50 to 100 centimetres of rainfall for its growth. A light well-drained soil capable of retaining moisture is ideally suited for the cultivation of the crop.” Which one of the following is that crop?

Cotton is grown on a variety of soils across the world. Deep, fertile soil with adequate humus and high water holding capacity and good internal drainage is best suited for growing cotton. Cotton can be grown in places wherever at least 180-200 frost-free days are available. The optimum temperature for germination is 20-30°C. Germination will be delayed if the temperature is < 18°C.

The climatic conditions in the cotton-growing regions of India show considerable variations. High temperature of about 45°C during sowing and seedling emergence and low temperature accompanied by occasional frost coinciding with the picking period and moderate rainfall ranging from 300-700 mm are the features of the north zone. In the Southern and Central zones, the climate is more uniform (equable).

The description in the question (subtropical, 210 frost-free days, 50-100 cm rainfall, light well-drained soil) aligns well with the requirements for cotton cultivation. Therefore, Option (a) is the correct answer.