If you think the price of a stock will decrease, you can:

Question $63$ options:

a$)$

None of the options

b$)$

buy puts, giving you the right to sell shares at the strike price even if the actual share price is lower

c$)$

you can sell $($or "write"$)$ puts, giving you an initial payment but also the obligation to buy shares if the stock falls to the strike price

d$)$

All of the options