On a dark night, a thin man of 6 feet tall walks away from a 24 feet high lamp post at a rate of 5 mph . How fast is the end of his shadow moving?

A \( 1 \frac{2}{3} \mathrm{mph} \)

B \( 2 \frac{2}{3} \mathrm{mph} \)

C \( 6 \frac{2}{3} \mathrm{mph} \)