Detailed Explanation:

A convex lens is thicker at the center and converges light rays. When an object is placed between the lens and its focal point, it produces a magnified, upright, virtual image—the principle behind magnifying glasses.

Concave lenses and plano-concave lenses diverge light and reduce image size, while convex mirrors also produce diminished images, making them unsuitable for magnification.

Therefore, a convex lens is used in magnifying glasses, making Option 2 the correct answer.