Questions

The Sukhoi Su-30MKI is a twinjet multirole air superiority fighter developed by Russia's Sukhoi and built under licence by India's Hindustan Aeronautics Limited (HAL) for the Indian Air Force (IAF).The BrahMos is a medium-range ramjet supersonic cruise missile that can be launched from submarine, ships, aircraft, or land. It is a joint venture between the Russian Federation's NPO Mashinostroyeniya and India's Defence Research and Development Organisation (DRDO) who together have formed BrahMos AerospaceThe name BrahMos is a portmanteau formed from the names of two rivers, the Brahmaputra of India and the Moskva of Russia.

‘prefer’ is a verb that is always followed by the preposition ‘to’ expressing choice or preference over something else. In this case choice of ‘this book’ over the ‘other’ one. ‘Than’ is used for comparing to options, ‘prefer to’ expresses choice. Correct expression will be ‘to that one’.