The answer would be B, (0,4) because of what happens when you plug these numbers in for x and y. For -6x+2y=8 you plug numbers in to make it -6(0)+2(4)=8 so then 8=8 which is a true statement. Then for the second equation, y=3x+4 you would plug in the numbers once more making it 4=3(0)+4 which is 4=4 resulting in a true statement. Therefore B would be the correct answer.
