A couple decides to save money for their child's first year college tuition. The parents will deposit 1700 n months from today and another 3400 2n months from today. All deposits earn interest at a nominal annual rate of 7.2%, compounded monthly. Calculate the maximum integral value of n such that the parents will have accumulated at least 6500 five years from today. (A) 11 (B) 12 (C) 18 (D) 24 (E) 25