Need help with these 3 questions. Pls answer if only 100% sure. Explain if possible.

*for the second one, I'm stuck between Standard deviation or Beta

Consider an investment opportunity set formed with two securities that are not perfectly negatively correlated. The global minimum-variance portfolio has a standard deviation that is always _________.

A. equal to the sum of the securities' standard deviations

B. equal to 0

C. greater than the standard deviation of risk-free asset

D. less than the standard deviation of risk-free asset

A measure of the total riskiness of an asset is ____________.

A. beta

B. covariance

C. standard deviation

D. alpha

Diversification can reduce or eliminate __________ risk.

A. all

B. firm-specific

C. systematic

D. market