A repairman charges $50 to diagnose a problem and $35 for each hour he works to fix the problem. Which equation can be used to model the total dollar amount, y, charged by the repairman to diagnose and fix a problem in x hours?
A) y = 50x + 35
B) y = 35x + 50
C) 35(x + 50)
D) 50(× + 35)