Geothermal corporation issued a press release before the stock market opened announcing that its earnings were 20% higher than last year's earnings. Explain how each of the following individual scenarios could be consistent with the semi-strong form of market efficiency. (a) When trading opened after the announcement, the stock price quickly decreased by 10%. (b) The stock price of Geothermal decreased slowly over the 30 days before the announcement. (c) The stock price increased by 10% immediately following the announcement but then decreased throughout the day so that the closing price was only 2% above the previous day. (d) The stock price of Geothermal did not change after the announcement was made public