Name one possible cross section of a sphere

The answer would be a circle. imagine a watermelon right, cutting it in half, you would see a circle that forms inside of the watermelon

A "cross section" is basically the two-dimensional face that you get when you cut a three-dimensional figure a certain way. For example, imagine you're buttering your bread. When you cut a pat of butter off, what shape is left on the butter? A square!

So, imagine cutting a ball in half. What shape is left? A circle!

Answer: circle