The correct answer is (b) R.K.S. Bhadauria.
Rakesh Kumar Singh Bhadauria is an Indian Air Force officer who is the 27th Chief of the Air Staff (CAS) of the Indian Air Force. He took over the office on 31 December 2021 from Air Chief Marshal R.N.C. Chaudhari.
Bhadauria was born on 15 December 1961 in Agra, Uttar Pradesh. He was commissioned into the Indian Air Force on 12 December 1980 as a fighter pilot. He has flown a variety of aircraft, including the MiG-21, MiG-23, MiG-29, and Su-30MKI.
Bhadauria has held various command and staff positions in the Indian Air Force. He has commanded a fighter squadron, a fighter wing, and an air base. He has also served as the Deputy Chief of the Air Staff (Personnel) and the Vice Chief of the Air Staff.
Bhadauria is a graduate of the National Defence Academy, Khadakwasla, and the Defence Services Staff College, Wellington. He also holds a Master of Arts degree in Defence Studies from the University of Madras.
Bhadauria is a recipient of the Param Vishisht Seva Medal, Ati Vishisht Seva Medal, and the Vishisht Seva Medal. He is also a foreign national of the Order of the Legion of Honour of France.
The other options are incorrect.
(a) H.S. Arora is a retired Indian Air Force officer who served as the 26th Chief of the Air Staff from 31 December 2016 to 31 December 2019.
(c) Ranjit Singh Dhanoa is a retired Indian Air Force officer who served as the 25th Chief of the Air Staff from 1 January 2017 to 31 December 2019.
(d) Vivek Ram Chaudhari is a serving Indian Air Force officer who is the Vice Chief of the Air Staff.