Assume That Markets Are Semi-Strong Form Efficient

Assume that markets are semi-strong form efficient. Suppose, then, that during a trading day, important new information is released for the first time concerning a certain company. This information indicates that one of the firm's oil fields, previously thought to be very promising, just came up dry. How would you expect the price of a share of stock to react to this information?

A) The value of a share will fall over an extended period of time as investors begin to sell shares in the company.
B) The value of a share will drop immediately to a price that reflects the value of the new information.
C) The value of a share will fall below what is considered appropriate because of the decreased demand for the shares, but eventually the price will rise to the correct level.
D) The value of a share will rise over a long period of time as investors sell the stock.
E) The stock price will not change since this type of information has no impact in markets that are semi-strong form efficient.