A Return Series Has an Arithmetic Mean of 12

A return series has an arithmetic mean of 12.8% and standard deviation of 7.8%. Assuming the returns are normally distributed what is the range of returns that an investor would expect to receive 95% of the time?

A) 12.8% to 20.6%
B) -10.6% to 36.2%
C) -2.8% to 28.4%
D) -12.8% to 20.6%
E) 10.6% to 36.2%