In light of this discussion, explain why the put-call parity relationship is valid only for European options on non-dividend-paying stocks. If the stock pays no dividends, what inequality for American options would correspond to the parity theorem?

Would you expect the hedge ratio to be higher or lower when the call option is more in the money? (Hint: Remember that the hedge ratio is the change in the option price divided by the change in the stock price. When is the option price most sensitive to the stock price?)