Can someone please explain the below question in details?

I'm really confused.

14) Dash Brevenshure works for the currency trading unit of ING Bank in London. He speculates that in the coming months the dollar will rise sharply vs. the pound. What should Dash do to act on his speculation?

A) Buy a call on the pound.

B) Sell a call on the pound.

C) Buy a put on the pound.

D) Sell a put on the pound.

Answer:C