Both reflecting and refracting telescopes suffer from :

Diffraction effects

Both reflecting and refracting telescopes suffer from diffraction effects.

Telescopes are monocular optical instruments, usually used in astronomy and are designed for the observation of remote objects. Telescopes have magnification for observing distant objects and use an arrangement of curved mirrors, lenses, or different devices. The two main kinds of telescopes are reflectors and refractors telescopes. The two telescopes suffer from diffraction effects such as the appearance of a rainbow of colours around the image.

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.

answer; ///i believe that the correct answer is (a) specialized cells)