Set Up an Equation and Solve the Following Problem

Multiple Choice

Set up an equation and solve the following problem. Andy starts walking from point A at 2 miles per hour. One-half hour later, Aaron starts walking from point A at 4 miles per hour and follows the same route. How long (in hours) will it take Aaron to catch up with Andy?

A) 1 hour
B) 0.45 hour
C) 0.75 hour
D) 0.5 hour