Answer:
The red polygon
Step-by-step explanation:
Think of the quadrants:
The "top right" one is quadrant I
The "top left" one is quadrant II
The "bottom left" one is quadrant III
The "bottom right" one is quadrant IV
When it says "reflected across y-axis", think of the y-axis as a "mirror"
Since the black polygon is in quadrant I, think of it looking into the mirror, or y axis. It is reflecting into quadrant II.
The red polygon is in quadrant II.
Sorry! I know this is a really weird explanation, but hope it helps!
