Ivonne has bought shares of RIO, Inc. stock for $25.00 per share. She expects a 1.00 dividend at the end of this year. After 2 years, she expects to receive a dividend of $1.25 and to sell the stock for $28.75. What is Ivonne's required rate of return?

a. 11.6

b. 11.35

please explain with formula if possible