Which of the following statements is true with regard to the erratic behaviour of Indian monsoons??

• A. Uniform duration but varying amounts of rain from one year to another, as well as at different places
• B. Uncertain date of onset and withdrawal, as well as unequal distribution of rain
• C. Uncertain date of onset and withdrawal as well as varying amounts of rainfall during different years
• D. Uniform duration but varying amounts of rain from place to place