A plumber charges $50 for every house call and an additional $70 for each hour of work. For one house call yesterday, the plumber earned $435.

Which equation can be solved to find the number of hours the plumber worked on the house call?

A. 435 = 70x + 50

B. 435 = (50+70)x

C. 435 = (x + 70) + 50

D. 435 = 50x + 70