Find the Mass of the Wire That Lies Along the Curve

Multiple Choice

Find the mass of the wire that lies along the curve r and has density δ.
-r(t) = 7i + ( 9 - 4t) j + 3tk, 0 $\le$ t $\le$ 2 $\pi$ ; = 5(1 + sin 7t)

A) 10 $\pi$ units
B) 50/7 + 50 $\pi$ units
C) 50 $\pi$ units
D) 100/7 + 50 $\pi$ units