A constant annual rate of dividend growth of 9 per cent is expected on a particular firm's ordinary shares for an indefinite period into the future. The next annual dividend in one year's time is expected to be $2.70. If the firm can earn 12 per cent per annum on similar risk investments to the firm itself, the value of the firm's ordinary shares is O a. $90 per share O b. $22.50 per share O c. $9 per share O d. $30 per share