Ed is on a road trip. He has already traveled 203 miles and is driving at a rate of 63 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 693 total miles?
A. 203x + 63 = 693
B. 63x + 693 = 203
C. 63x + 203 = 693
D. 203x + 693 = 63