John is investing in the S&P 500. His expected return on the S&P 500 is 10% with a standard deviation of 4%. If John is investing $200,000, then what is the dollar range of returns that John can have with 90 percent confidence at the end of the year?
a. $212,000 - $228,000
b. $206,840 - $233,160
c. $204,320 - $235,680
d. $199,400 - $240,600