Which of the following statement describes about the American and European option contract? Select one: O a. The European-type option gives the option buyer the right, not the obligation, to exercise the option only on the contract expiration date. O b. The American-type option gives the option buyer the right, not the obligation, to exercise the option at any time up to the contract expiration date. c. American-type options over listed shares are more common than European-type options. O d. All of the given answers