Answer: The exercise price of the option.

The value of a European put option is **directly related** to the exercise price. This is because a higher exercise price increases the potential payoff of the put option, making it more valuable. On the other hand, the value of a European put option is **inversely related** to the risk-free interest rate and the value of the underlying asset. A higher risk-free rate reduces the present value of the exercise price, while a higher underlying asset value decreases the likelihood of the put option being exercised.

Author: LeetQuiz Editorial Team