Which of the following statements is (are) correct?

a. If a market is semi-strong-form efficient, it is also strong-form efficient.

b. If a market is not strong-form efficient, it must be neither semi-strong- nor weak-form efficient.

c. If a market is weak-form efficient, it is also semi-strong-form and strong-form efficient.

d. If a market is not semi-strong-form efficient, it must also be not weak-form efficient.

e. If a market is not weak-form efficient, it must be neither semi-strong- nor strong-form efficient.