AMC 12 2007b Problem 9

A function $f$ has the property that $f(3x-1)=x^2+x+1$ for all real numbers $x$. What is $f(5)$?

$\mathrm {(A)} 7 \mathrm {(B)} 13 \mathrm {(C)} 31 \mathrm {(D)} 111 \mathrm {(E)} 211$