Given the annual returns below, which investment is the most risky (using standard deviation as the risk measure)? Year 1 Year 2 Year 3 Standard Dev Inv. A 4% -3% 8% 5.57% Inv. B 8% -7% 13% 10.41% Inv. C 9% -10% 23% 16.56% Inv. D -6% -9% 11% 10.79%