Assertion: Magnification of a convex mirror is always positive, but that of a concave mirror may be both positive and negative. Reason: It depends on the sign convention chosen.A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.C. Assertion is correct but reason is incorrect.D. Both Assertion and Reason are incorrect.

The correct answer is D. Both Assertion and Reason are incorrect.

Here's why:

Assertion: The magnification of a convex mirror is always positive. This is incorrect. In fact, the magnification of a convex mirror is always negative because convex mirrors always form virtual images that are upright and smaller than the object.

Reason: It depends on the sign convention chosen. This is also incorrect. The magnification of a mirror (both convex and concave) depends on the nature of the mirror and the position of the object. For convex mirrors, magnification is negative, and for concave mirrors, magnification can be positive or negative depending on whether the image is real or virtual. The sign convention does not change this fundamental property.