Which statement is MOST CORRECT concerning the Beta of the Market Portfolio (BM )?

a. BM = 1 since the Covariance(RM,RM) / Variance(RM) = 1

b. (-1) < BM < (+1)

c. BM is indexed to be 1.0 for any period over which it is measured.

d. BM is approximately, or most often 1.0

e. BM is 1.0 if CAPM holds, since the Security Market Line equation implies algebraically that in an efficient market BM = 1