In Periods of Boom, Which Leads to Economic Instability, Reserve

In periods of boom, which leads to economic instability, Reserve Bank resorts to

A) sale in the market of first class securities in its possession to reduce the supply of money as a measure of open market operations
B) buying of approved securities in the market as a measure of pen market operations
C) hike in the bank rate as a measure of open market operations
D) none of these