Final answer:
The focal length of a lens appears magnified by approximately 1.5 times on an APS-C size sensor, essentially giving the lens a longer effective focal length and a narrower angle of view.
Step-by-step explanation:
When used with a digital camera that has an APS-C size sensor, the focal length of a lens appears magnified by approximately 1.5 times. This is due to the smaller sensor size compared to a full-frame sensor, which results in a crop factor. For example, a lens with a 50.0 mm focal length would act as a 75.0 mm lens on an APS-C sensor camera. This multiplication factor is what gives APS-C cameras their inherent zoom capability for a given lens, leading to a narrower angle of view when compared to the same lens on a full-frame camera.
Selecting option (b) from the choices provided, it gives a narrow range of view. The image appears to be farther than the actual object, which aligns with the characteristics of a longer focal length brought on by the crop factor of the APS-C sensor.