A corporation can earn 7.5% if it invests in municipal bonds. The corporation can also eam 8.40% (before-tax) by investing in preferred stock. Assume that the two investments have equal risk. What is the break even corporate tax rate that makes the corporation indifferent between the two investments? Assume a 70% dividend exclusion for tax on dividends. (Do not found your intermediate answer and round your final answer to two decimal places.) a. 43.93% 1.27.50% O. 32.50% d. 35.71% Oe.28.57%