Which expression is equivalent to 8x − 2x + 4 and why?

4 + 6x, because (8x − 2x) + 4 = 6x + 4 = 4 + 6x
10x, because 8x − 2x + 4 = 6x + 4 = 10x
8x + 2x, because 8x − (2x − 4) = 8x + 2x
14x, because 8x − 2x + 4 = 8x + 6x = 14x