(a) 1 only
During the rule of Iltutmish, Chenghiz Khan defeated Jalal al-Din near the banks of Indus.
Hence statement 1 is correct.
Muhammad Bin Tughluq was the sultan of Delhi from 1325 to 1351 AD. In 1398 AD, Timur invaded India. He crossed the Indus and ravaged Multan and Punjab.
Hence statement 2 is not correct.
Deva Raya II of the Vijayanagara empire ruled between 1422 and 1446 AD. Vasco Da Gama reached the coast of Kerala in 1498.
Hence statement 3 is not correct.