What does standard error and alpha measure in a regression?

• A. standard error is the standard deviation of the alphas. Alpha or the specific excess return is not explained by the market.

• B. Standard error is the mean of residuals and alpha is the specific excess return which is explained by the market.

• C. Standard error is the standard deviation of beta and alpha is the specific excess return which is not explained by the market.

• D. Standard error is the standard deviation of residuals and alpha is the specific excess return which is not explained by the market.