Which of the following statements is true about weak-form tests?

a) Weak-form tests are tests of the efficacy of fundamental analysis.

b) The small-firm effect is a market anomaly found in weak-form tests.

c) Weak-form tests examine the effects of public events on the company's stock price.

d) They are usually based on the stock's P/E ratio or its market capitalization.

e) They are often based on tests of serial correlation of stock market returns.