In the given question, the sentence is divided into three parts I, II, and III. For each part, an alternative statement is also given. You have to determine if a part requires a correction and then mark that as your answer.

Beside, central banks have been / active in purchasing actual gold / to protect its currencies against depreciation.

I. Besides, central banks have been 

II. active into purchasing actual gold

III. to protect their currencies against depreciation.