Which one of the following is FALSE on the marginal investors to obtain the effective tax shield of debt?

Which one of the following is FALSE on the marginal investors to obtain the effective tax shield of debt?

They are indifferent to investing in debt or equity if the after$-$tax rate$-$free return is the same

Their required risk$-$free return is reflected in market data

Their behavior is representative of an average investor of the firm

They have influences on the market prices of the firm$$s securities