Which of the following statements concerning market efficiency is true?

		a. If the market is weak-form efficient, it is also semistrong-form efficient.
		b. If the market is semistrong-form efficient, it is also strong-form efficient.
		c. If the market is weak-form efficient, it is also strong-form efficient.
		d. If the market is semistrong-form efficient, it is also weak-form efficient.