If you write a put option you...:

a$)$ may exercise the option if the stock price rises.

b$)$ may be forced to buy the underlying stock for the exercise price.

c$)$ hope the stock price falls.

d$)$ have the right to sell the underlying stock for the exercise price.

e$)$ have the right to remain silent.

f$)$ have the right to buy the underlying stock for the exercise price.