Explanation:

Then Northern India would be a cold desert. Statement 2 is incorrect. Monsoon and Monsoon rainfall are two different things. Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation. But it is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea. So, Monsoon would still be there but, monsoon rainfall on the part of northern India may not be there because of absence of Himalayas. However, Monsoon rainfall would also be there at the Western Ghats region. Statement 3 is incorrect. The Indus, the Ganga and the Brahmaputra comprise the Himalayan river systems. The Himalayan Rivers existed even before the formation of Himalayas i.e. before the collision of Indian Plate with the Eurasian plate. (Antecedent Drainage) They were flowing into the Tethys Sea. These rivers had their source in the now Tibetan region. The deep gorges of the Indus, the Satluj, and the Brahmaputra etc. clearly indicate that these rivers are older than the Himalayas. Hence, if there would be no Himalaya, then also these mentioned rivers would be there.