The stock market is trading at a forward price-to-earnings of 16 times, price- to-book of 2.2 times, and the 10-year Treasury is at 1.5 percent. Given the fact that market volatility has risen recently, what is the current stock market's equity risk premium? O a. 1.5 percent O b.4.1 percent O c. 4.8 percent O d. 6.3 percent