Before 1949, the RBI also acted as Central Bank for which countries?

Question:

Before 1949, the RBI also acted as Central Bank for which countries?

Hints:

1. For one country RBI acted as central bank until April 1937.
2. For another country RBI was central bank until June 1948.

Options:

A. China and Pakistan

B. Pakistan and Bhutan

C. Bhutan and Srilanka

D. Pakistan and Burma