please choose the correct answer and explain it.

A bank account is credited interest using a force of interest of 8, = 0.01 +0.04. Calculate the balance in dollar at t-4 if the balance at t-2 is $500. (Continued from the last question.) Another bank account is credited an annual interest of k compounded quarterly, and the interest is equivalent to the last question between t-2 and t-4. Determine k. 13.9% 13.05 29.75 14.85 13.2) 26.9% 17.0%