A point with a positive x-coordinate and a negative y-coordinate is reflected over the y-axis. Which sentence describes the coordinates of the new point?

The x-coordinate is negative, and the y-coordinate is negative.

This is because the y-axis is vertical, so reflecting across it means you will change the sign of the x-value, and the sign of the y-value will stay constant. Since we start off with a positive x and negative y, we will end up with a negative x and negative y.