In order to reflect a point over the y-axis, the only thing you have to do is to change the sign of the x-coordinate of the original point, then when the x-coordinate of your point has a negative sign just take the same magnitude but with positive sign for the x-coordinate, like this:
C(-4, 3) -> C'(4, 3)
When you want to translate some units down a point, you have to subtract the units to translate from the y-coordinate of the point, like this:
C'(-4, 3) -> C''(4, 3-4) = C''(4, -1)
Then, after the reflection over the y-axis and translation 4 units down of a point located at (-4, 3) we get (4, -1), then, the correct answer is the second option.