Mike borrows X from a bank that charges an effective rate of 10 % a year. He repays the loan with payments at the end of every six months for n years. The interest paid in the first payments is $ 2,928.53. The interest paid in the last payment is $ 209.83. Find n.

A 11 years

B 12 years

C 13 years

D 14 years

E 15 years