Please answer the question and give the procss of calculation

An adjustable rate mortgage with a teaser start rate of 1.5%, an index of the 11th District COFI rate, a margin of 2.0%, and periodic and lifetime caps of 2/6 with semi-annual adjustments, would have a maximum interest rate of what at the beginning of the fourth loan year if the 11th District COFI rate is 6.5% at that time?

a) 5.5% b) 6.5% c) 7.5% d) 8.5%