Ed is on a road trip. He has already traveled 248 miles and is driving at a rate of 70 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 644 total miles?

A.
70x + 248 = 644

B.
248x + 644 = 70

C.
70x + 644 = 248

D.
248x + 70 = 644