Who among the following replaced Morarji Desai as the Prime Minister of India in 1979?

Charan Singh

The correct answer is Option 3 - Charan Singh

In 1979, Charan Singh succeeded Morarji Desai as the Prime Minister of India. This transition occurred due to a political crisis within the ruling Janata Party coalition government, which led to the resignation of Morarji Desai from the Prime Minister's position.
Charan Singh, a prominent politician and leader from Uttar Pradesh, was chosen as the consensus candidate to replace Morarji Desai. He belonged to the Bharatiya Lok Dal (BLD), a party formed by former members of the Janata Party.