Chris has $100 in his savings account and he adds $20 a month to the account. The total amount can be represented by the linear function T = 20x + 100. His goal is to have a total of $300 in four more months. What should he change in the function to reach this goal? A) Change the amount he adds each month to $50. B) Change the amount he adds each month to $40. C) Change the y-intercept of the linear function to $20. D) Change the y-intercept of the linear function to $50.