sell it at today’s price, with hopes that by the time you have to re-purchase the share to return what you borrowed, the price will be lower. You’re hoping the market price will go down.

An option is simply a contract that gives you the right to buy a share (during some window of time) at a specific price. With a publicly traded option, you buy that option with hopes that at some point during your exercise window, the market price of the stock will be higher than whatever is the specific purchase price the option entitleds you to. You’re hoping the market price of the stock will go up.