When using the CAPM to estimate the cost of equity for evaluation of investment proposals, the appropriate substitute for the risk free rate of interest is:

		The yield on ten year government bonds.
		The yield on a government security whose term to maturity matches the life of the proposed project.
		The yield on a 30-year government bond.
		The yield on three year government bonds.
		The yield on 90 day treasury notes.

Please explain your answer. Thanks