Explanation:

The legendary playback singer S. P. Balasubrahmanyam was posthumously awarded the Padma Vibhushan, India's second-highest civilian honor, in 2021 for his exceptional and distinguished service in the field of arts. Therefore, option B is correct. Option A, Indu Jain, a media baroness, also received a Padma Bhushan (not Vibhushan) in 2016 and passed away in 2021, but not posthumously awarded Padma Vibhushan in 2021. Option C, Milkha Singh, the 'Flying Sikh', passed away in 2021 but was not posthumously awarded the Padma Vibhushan in that year. Option D, Basu Chatterjee, a renowned filmmaker, passed away in 2020 and was not a posthumous Padma Vibhushan recipient in 2021. Thus, A, C, and D are incorrect.