Cost of capital is based on source of capital, and weights of capital, therefore major components include cost of equity, cost of debt, and their weight-age thus the debt to equity ratio plays an important role,
correct option is optimal debt - equity ratio, this ratio depicts the proportion of debt to equity.
The percent of increase is 1%. To figure this out, simply reason that 1% of $100 is $1. Therefore, because $300 is a threefold increase, 1% would be $3.