A firm sold a 10-year bond issue 3 years ago. The bond has a 6.45% annual coupon and a $1,000 face value. The coupons are paid annually. If the current market price of the bond is $951.64 and the tax rate is 35%, what is the after-tax cost of debt? (round to the nearest hundredth percent)

		a. 4.64%
		b. 4.78%
		c. 7.14%
		d. 7.36%
		e. None of the above