im confused on this one, thank you!

Barry Cuda is considering three different investments. He, like most investors, is concerned about minimizing risk. Using the following information, which investment appears to have the least amount of risk relative to its expected return? Investment A: expected return was calculated to be $20,000 with a standard deviation of $8000. Investment 8 ; expected return was calculated to be 16% with a standard deviation of 7%. Investment C: expected return was calculated to be 21% with a standard deviation of 9%. Investment A Investment B Investrient C Either Investment B or C