Which of the following statement is true? The upper bound for American put options on stocks is 0. An option that can be exercised any time before its expiration date is called a European option. A put option gives the owner the right but not the obligation to buy an asset at a given price (i.e. the exercise price), The buyer of a call option on shares has the right to exercise the option, but the writer of the call option has the obligation to deliver the shares at the exercise price upon exercise