Your retirement goal is to have $3,000,000 available ("in the bank") when you retire at age 67. Suppose your contribution into that plan consisted entirely of equal annual payments, commencing at age 31 and ending at age 67 . What is the size of the contribution needed to achieve your goal? Assume a 6% annual interest rate. a. $50,005.30 b. $51,455.38 c. $23,505.30 d. $23,572.28