​Under which Act was the Central Legislature made of two houses?​

Correct option is B

The Government of India Act of 1919 established a bicameral legislature for the Central Legislature of India, consisting of the Legislative Assembly and the Council of State: 

• Legislative Assembly

The lower house, with 145 members who served three-year terms. 104 members were elected and 41 were nominated. 

• Council of State

The upper house, with 60 members who served five-year terms. 34 members were elected and 26 were nominated. The Council of State reviewed legislation passed by the Legislative Assembly.