II$.$ These results show that the formula does not make sense if the expected growth rate is equal to or less than the required rate of return.

III. These results show that the formula does not make sense if the required rate of return is equal to or less than the expected growth rate.

IV$.$ These results show that the formula does not make sense if the required rate of return is equal to or greater than the expected growth rate.

V$.$ These results show that the formula makes sense if the required rate of return is equal to or less than the expected growth rate.

c$.$ Is it reasonable to think that a constant growth stock could have $g>r_s?$

I. It is not reasonable for a firm to grow indefinitely at a rate higher than its required return.

II$.$ It is reasonable for a firm to grow indefinitely at a rate higher than its required return.

III. It is not reasonable for a firm to grow even for a short period of time at a rate higher than its required return.

IV$.$ It is not reasonable for a firm to grow indefinitely at a rate lower than its required return.

V$.$ It is not reasonable for a firm to grow indefinitely at a rate equal to its required return.