Consider the following Bhakti Saints:<br/>1. Dadu Dayal<br/>2. Guru Nanak<br/>3. Tyagaraja<br/><br/>Who among the above was/were preaching when the Lodi dynasty fell and Babur took over?

Key date: Lodi dynasty fell and Babur took over in 1526 (First Battle of Panipat).

1. Dadu Dayal — He lived c. 1544–1603. He was born after 1526, so he was not preaching when the Lodis fell. Verdict: Incorrect.
2. Guru Nanak — He lived 1469–1539. He was active during Babur’s invasion and even referred to it in the Babarvani hymns. Verdict: Correct.
3. Tyagaraja — He lived 1767–1847, much later than Babur. Verdict: Incorrect.

Hence, only 2 fits.