AMC 8 2017 Problem 6

If the degree measures of the angles of a triangle are in the ratio $3:3:4$, what is the degree measure of the largest angle of the triangle? $\textbf{(A) }18 \textbf{(B) }36 \textbf{(C) }60 \textbf{(D) }72 \textbf{(E) }90$