The correct answer is: D. firm cannot control
Interest rates, tax rates, and market risk premium are all factors that are beyond the control of any individual firm. These factors are determined by the overall economy and by government policy. Firms can try to mitigate the impact of these factors by hedging their positions, but they cannot eliminate them altogether.
Interest rates are the cost of borrowing money. When interest rates are high, it costs firms more to borrow money, which can reduce their profits. Tax rates are the amount of money that firms have to pay to the government. When tax rates are high, it reduces the amount of money that firms have to keep, which can also reduce their profits. The market risk premium is the additional return that investors expect to earn on stocks over and above the return on risk-free assets. When the market risk premium is high, it means that investors are expecting higher returns from stocks, which can make it more expensive for firms to raise capital.
All of these factors can have a significant impact on a firm’s profitability. Firms need to be aware of these factors and take steps to mitigate their impact, but they cannot control them.