Ed is on a road trip. He has already traveled 221 miles and is driving at a rate of 61 miles per hour. Which equation could be used to find how many hours, x, Ed has left in his road trip if he is traveling 631 total miles?
A.
61x + 221 = 631

B.
61x + 631 = 221

C.
221x + 61 = 631

D.
221x + 631 = 61