Definite article singular vs plural noun

Question

Consider these:

A. The deer eats the berry of the mistletoe.
B. Deer eat berries of mistletoes.
C. (The) deer eat(s) (the) berry(es) of (the) mistletoe(s).

B is the way I would usually write a sentence of the given meaning. The use of the, the definite article, to refer all the things which the noun concerns, is not familiar with me - the reason I am having trouble with A and C.

Questions:

1. In C, how would you choose the articles? The most common way and, if any, the most formal way.

2. What if there is chance of misleading because there is already something to which the + singular may refer?

Answer 1

I would write:

The deer eats mistletoe berries. (referring to one deer)

or

Deer eat mistletoe berries. (referring to more than one deer or deer in general)

berries should be used because a deer is unlikely to eat just one berry.

Making mistletoe an adjective eliminates that question as it automatically becomes singular.