An adjustable rate mortgage loan with a teaser start rate of $1\mathrm{.}5\%$ for the first loan year, an index of the $30-$day SOFR, a margin of $2\mathrm{.}0\%,$ a periodic annual interest rate increase cap of $2\%$ and a lifetime interest rate cap of $8\mathrm{.}5\%$ with annual adjustments, would have a maximum interest rate of what for the fourth loan year if the $30-$day SOFR is $4\mathrm{.}5\%$ at that time?

a$)5\mathrm{.}5\%$

b$)6\mathrm{.}5\%$

c$)7\mathrm{.}5\%$

d$)8\mathrm{.}5\%$