Which of the following would tend to reduce the weighted average cost of capital for a firm?

The expected return on the market portfolio decreases but the risk-free rate stays the same

The flotation costs associated with issuing new common stock increase

The companys beta increases

The firms corporate tax rate decreases but does not change the firms beta

The firm, with a required return on equity greater than its borrowing rate, retires some debt with money raised through issuing more equity