Option (a) is the correct answer: 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. Optimum temperature for germination 20-300C. Germination will be delayed if the temperature is <180C. The climatic conditions in the cotton growing regions of India show considerable variations. High temperature of about 45 degree celcius during sowing and seeding 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 equal.