The correct option is
A A-4, B-1, C-2, D-3
The Constituent Assembly in addition to the making of Constitution also performed other functions as:
It adopted the National Flag on July 22, 1947.
It adopted the National song as well as National Anthem on January 24, 1950
The National emblem was adopted on December 1947 for "Dominion of India" (the period between 15 August 1947 to 26 January 1950) and it was officially adopted on 26 January 1950 when India became Republic.
The National Calendar to be used officially was adopted on March 22, 1957.