The HMS Dreadnaught Is 20 Miles North of Montauk and Steaming

The HMS Dreadnaught is 20 miles north of Montauk and steaming due north at 10 mph, while the USS Mona Lisa is 25 miles east of Montauk and steaming due east at an even 15 mph. How fast is their distance apart increasing Round your answer to the nearest whole number.

A) 15 miles per hour
B) 23 miles per hour
C) 36 miles per hour
D) 52 miles per hour
E) 18 miles per hour