Which option provides the right to sell at a specified strike price?

The correct choice is the put option, which grants the holder the right to sell an underlying asset at a predetermined strike price within a specified period. This financial instrument is primarily used by investors to hedge against potential declines in asset prices or to speculate on bearish market movements. When an investor purchases a put option, they can sell the underlying asset at the agreed-upon strike price, even if the market price drops below that amount, thereby limiting their potential losses.

In contrast, a call option gives the buyer the right to buy an asset at a specified price, so it does not fit the description of selling. Index options and interest rate options are specific varieties of financial derivatives based on different underlying assets or metrics but do not inherently grant the right to sell. Therefore, the put option is the only choice that correctly aligns with the ability to sell at a specified strike price.