If equation one is 3x + 2 = y, and equation two is x + 4 = 2y, which of the following would be the best first step toward finding their solution?
(A) substituting 3x + 2 for y in 
     equation two 
(B) substituting x + 4 for y in 
     equation two 
(C) substituting x + 4 for y in 
     equation one 
(D) substituting 3x + 2 for x in 
     equation two