If the financial markets are efficient then:

a. stock prices will change only when an event actually occurs, not at the time the event is anticipated.

b. stock prices should respond only to unexpected news and events.

c. stock prices should increase or decrease slowly as new events are analyzed and the information is absorbed by the markets.

d. stock prices should remain constant.

e. an increase in the value of one security should be offset by a decrease in the value of another security.