There is external and internal so I'll list th external. The most important is skin then mucus, sweat or secretion, hair, nails and tears which are all part of the integumentary. Some internal defenses are white blood cells and T cells.
A is true because they do have a true nucleus or membrane-bound organelles .
I’m pretty sure the answer is c. Protista. Hope this helps!
Resolving power<span> is the ability of an imaging device to separate (i.e., to see as distinct) points of an object that are located at a small angular distance or it is the </span>power<span> of an optical instrument to separate far away objects, that are close together, into individual images.</span>
