In Single-Telescope Astronomical Systems, Either Optical or Radio, the

In single-telescope astronomical systems, either optical or radio, the

A) longer the wavelength, the sharper the image.
B) smaller the main mirror or lens or radio dish aperture in general, the sharper the image.
C) larger the main mirror or lens or radio dish aperture in general, the sharper the image.
D) longer the focal length of the primary mirror or lens or radio dish, the sharper the image.