Choice "B" is correct. The benefits of debt financing over equity financing are likely to be highest if marginal tax rates are high (because interest on debt is deductible for tax purposes) and if there are few noninterest tax benefits (because there is little or no reason to depart from debt financing).
Choice "a" is incorrect. The benefits of debt financing over equity financing are likely to be highest if marginal tax rates are high, not low (because interest on debt is deductible for tax purposes), and if there are few noninterest tax benefits.
Choice "d" is incorrect. The benefits of debt financing over equity financing are likely to be highest if marginal tax rates are high (because interest on debt is deductible for tax purposes) and if there are few, not many, noninterest tax benefits.
Choice "c" is incorrect. The benefits of debt financing over equity financing are likely to be highest if marginal tax rates are high, not low (because interest on debt is deductible for tax purposes), and if there are few, not many, noninterest tax benefits.