Which of the following is not true regarding currency options?

a$.$ The buyer of a put option has the right to sell the currency at the strike price.

b$.$ The writer of a call option has the obligation to sell the currency to the buyer if the option if exercised.

c$.$ The writer of a put option has the obligation to sell the currency to the buyer if the option is exercised.

d$.$ The buyer of a call option has the right to buy the currency at the strike price.