A Uniform Wire Is Bent into a Semi-Circle of Radius $\pi$

Multiple Choice

A uniform wire is bent into a semi-circle of radius R and laid out such that it is entirely in the x-y plane .The semicircle has its ends fixed on the x axis at x = -R and x = +R.With the exception of its end points,the semicircle is entirely above the x-axis (i.e.the y-coordinates of all points on its arc are positive) .What is the y coordinate of its center-of-mass?

A) 2R/ $\pi$
B) R/3
C) R/2
D) 2R
E) R/