In 1946, who among the following was made the interim president of the Indian Constituent Assembly?

Sachchidananda Sinha

The correct answer is Option 4 - Sachchidananda Sinha

Of the choices you likely have, the interim president of the Indian Constituent Assembly in 1946 was Sachidananda Sinha.
It's important to note that Dr. Rajendra Prasad became the permanent president soon after.