With referance to India, Which one of the following statements is not correct ?

• A. About one-third of the area of the country records more than 750 millimetresof annual rainfall
• B. The dominant source of irrigation in the country is wells.
• C. Alluvial soil is the predominant type of soil in the northern plains of the country
• D. The mountain areas account for about thirty percent of the surface area of the country