Joint Products Inc., a corporation with a 40% marginal tax rate, plans to issue $1,000,000 of 8% preferred stock in exchange for $1,000,000 of its 8% bonds currently outstanding. The firms total liabilities and equity are equal to $10,000,000. The effect of this exchange on the firms weighted average cost of capital is likely to be a. no change, since it involves equal amounts of capital in the exchange and both instruments have the same rate. b. a decrease, since a portion of the debt payments are tax deductible. c. a decrease, since preferred stock payments do not need to be made each year, whereas debt payments must be made. d. an increase, since a portion of the debt payments are tax deductible.