Which of the following statements about market efficiency is true?
Group of answer choices
O A market can be semi-strong form and strong-form efficient but not weak-form efficient.
O A market can be semi-strong form efficient but not weak-form efficient.
O A market can be semi-strong form, weak-form or strong-form efficient but not all simultaneously.
O A market must be weak-form efficient if it is semi-strong form efficient.
O A market must be weak-form efficient if share prices are random.