Returns for the Dayton Company over the last 3 years are shown below. What's the standard deviation of the firm's returns? (Hint: This is a sample, not a complete population, so the sample standard deviation formula should be used.) Do not round your intermediate calculations.

Year		Return
1		28.00%
2		-12.50%
3		40.00%

a. 13.79%

b. 11.26%

c. 22.46%

d. 27.51%

e. 38.90%