Final answer:
A watch glass with uniform thickness and a large curvature radius placed in the path of a beam of parallel light will not disperse or deviate the light, thus the beam will (c) undergo no deviation.
Step-by-step explanation:
When a beam of parallel light enters a watch glass with uniform thickness and a large average radius of curvature, the behavior of light will be different from that with a prism or a lens. Unlike a prism, which has angular surfaces that cause dispersion, and thus would split light into its components colors, the watch glass' smooth curvature does not induce such dispersion due to its shape. Also, the watch glass does not have the necessary shape to converge or diverge light like a lens would.
A converging lens focuses parallel rays to a point, while a diverging lens causes parallel rays to spread out. Since neither of these conditions aptly describe a watch glass, the correct answer is that the light beam will undergo no deviation as it passes through the uniform thickness of the glass and exits in the same parallel manner as it entered, assuming there's no significant optical effect due to the curvature or any refractive index difference between the air and the glass material.