Matt invests in an account now (that is, at t = 0) that pays a force of interest &= kt, where k is a constant and t > 0. His deposit will triple in value over 20 years' time. Suppose you want to invest in an identical account so that your investment exactly doubles by 20 years from now. Find the time T > 0, expressed in years, at which you should make your deposit. a. 10.37 b. 14.35 C. 13.16 d. 9.22 e. 6.89