Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

In practice, both a fixed parity regime and a target zone regime allow the exchange rate to float within a band around the parity level. The most likely rationale for the band is that the band allows the monetary authority to:
Option A:be less active in the currency market.
Option B:earn a spread on its currency transactions.
Option C:exercise more discretion in monetary policy.

Answer: C