Question

what is a practical use of a convex lens?
magnifying glass
reflecting objects
separating white light into colors
making this smaller & clearer

Explanation:

A convex lens converges light and is used in magnifying glasses to magnify objects (make them appear larger). Reflecting objects is for mirrors, separating white light into colors is for prisms, and convex lenses don't make objects smaller. So the practical use of a convex lens here is as a magnifying glass.

Answer:

A. Magnifying glass