The correct answer is D. Avtar Singh.
Shiv Thapa, Manoj Kumar, and Vikash Krishan were all members of the Indian boxing team at the 2016 Summer Olympics in Rio de Janeiro. Avtar Singh was not a member of the team.
Shiv Thapa is an Indian professional boxer who competes in the men’s flyweight division. He is a two-time Olympian, having represented India at the 2012 Summer Olympics in London and the 2016 Summer Olympics in Rio de Janeiro. Thapa is also a two-time Asian Games medalist, having won a bronze medal at the 2010 Asian Games in Guangzhou and a silver medal at the 2014 Asian Games in Incheon.
Manoj Kumar is an Indian professional boxer who competes in the men’s light welterweight division. He is a two-time Olympian, having represented India at the 2008 Summer Olympics in Beijing and the 2012 Summer Olympics in London. Kumar is also a two-time Commonwealth Games medalist, having won a gold medal at the 2010 Commonwealth Games in Delhi and a silver medal at the 2014 Commonwealth Games in Glasgow.
Vikash Krishan is an Indian professional boxer who competes in the men’s middleweight division. He is a two-time Olympian, having represented India at the 2012 Summer Olympics in London and the 2016 Summer Olympics in Rio de Janeiro. Krishan is also a two-time Asian Games medalist, having won a bronze medal at the 2010 Asian Games in Guangzhou and a silver medal at the 2014 Asian Games in Incheon.
Avtar Singh is an Indian professional boxer who competes in the men’s light heavyweight division. He is a former Asian Games bronze medalist, having won the medal at the 2010 Asian Games in Guangzhou. Singh was not selected for the Indian boxing team at the 2016 Summer Olympics in Rio de Janeiro.