A Man 6 Feet Tall Walks at a Rate of Feet

A man 6 feet tall walks at a rate of feet per second away from a light that is 15 feet above the ground (see figure) . When he is feet from the base of the light, at what rate is the Tip of his shadow moving?

A) $\frac { 1 } { 2 } \mathrm { ft } / \mathrm { sec }$
B) $50 \mathrm { ft } / \mathrm { sec }$
C) $\frac { 3 } { 50 } \mathrm { ft } / \mathrm { sec }$
D) $\frac { 9 } { 2 } \mathrm { ft } / \mathrm { sec }$
E) $\frac { 50 } { 3 } \mathrm { ft } / \mathrm { sec }$