Which of the following statements is true?

None of these.

American options are options on securities of U.S. corporations, and the options are traded on American exchanges. European options are options on securities of U.S. corporations, but the options are traded on European exchanges.

American options are options on securities which are traded on American exchanges. European options, also traded on American exchanges, are options on European corporations.

American options may be exercised anytime up to expiration. European options may be exercised only at expiration.