Problem:

One way to calculate a stock's beta is to

a. calculate the stock's coefficient of variation.

b. calculate both the stock's mean return and the std.dev. of the returns.

c. regress the stock's past returns against the risk-free rate.

d. regress the stock's past returns against past market return.

e. draw a trend line using past measures of the stock's beta.

Explain in detail and show all work.