Which fact becomes correct because the Deccan Plateau slopes toward the east and south-east?

Correct answer: Many major peninsular rivers flow toward the Bay of Bengal

The governing concept is that surface drainage generally follows the slope of land. Much of the Deccan Plateau slopes eastward or south-eastward, so major east-flowing peninsular rivers such as the Godavari, Krishna and Cauvery move across the plateau and eventually enter the Bay of Bengal. Therefore, option A is correct. The word “many” is important: it does not claim that every river flows east, because the Narmada and Tapi flow west into the Arabian Sea. The other choices incorrectly deny Deccan rivers or assign them Himalayan origins.