G. Madhavan Nair is a former chairman of the Indian Space Research Organisation (ISRO). He was appointed as the chairman of ISRO in 2003 and served in that position until 2009. During his tenure, ISRO achieved several major milestones, including the successful launch of the Chandrayaan-1 mission to the Moon and the Mars Orbiter Mission.
Bharat Heavy Electricals Limited (BHEL) is a public sector undertaking under the Ministry of Heavy Industries and Public Enterprises. It is a leading manufacturer of power generation equipment, including boilers, turbines, generators, and transformers.
Oil and Natural Gas Corporation (ONGC) is a state-owned oil and gas company. It is the largest oil and gas company in India and one of the largest in the world.
Steel Authority of India Limited (SAIL) is a state-owned steel company. It is the largest steel company in India and one of the largest in the world.
Therefore, the correct answer is B.