Constituent Assembly consisted of how many members?

Three hundred

The correct answer is Option (1) → Three hundred

The Constituent Assembly had 300 members. Of these, six members played particularly important roles. Three were representatives of the Congress, namely, Jawaharlal Nehru, Vallabh Bhai Patel and Rajendra Prasad. It was Nehru who moved the crucial "Objectives Resolution", as well as the resolution proposing that the National Flag of India be a "horizontal tricolour of saffron, white and dark green in equal proportion", with a wheel in navy blue at the centre. Patel, on the other hand, worked mostly behind the scenes, playing a key role in the drafting of several reports, and working to reconcile opposing points of view. Rajendra Prasad's role was as President of the Assembly, where he had to steer the discussion along constructive lines while making sure all members had a chance to speak.

So, the correct option is [1].