<h3>
Answer:</h3>
The Correct answer is... <em>C.</em><em> Protists are a catch-all group for eukaryotes that aren't plants, fungi, or animals</em>.
<h3>
Explanation:</h3>
Let's break it down!
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A. Protists are all <u>heterotrophic</u>.
The given statement in answer choice A. is (partially correct) FALSE.
<em>The following statement is TRUE... The protist is classified as </em><em>either</em><em> </em><u><em>autotrophs</em></u><em> or </em><u><em>heterotrophs</em></u><em>.</em>
~~~
B. Protists can't <u>live in freshwater</u>.
The given statement in answer choice B. is also FALSE.
<em>TRUE... Nearly </em><em>all protists exist</em><em> in </em><u><em>some type of aquatic environment</em></u><em>, </em><u><em>including freshwater</em></u><em>.</em>
~~~
C. Protists are a catch-all group for <u>eukaryotes</u> that aren't <u>plants, fungi, or animals</u>.
The given statement in answer choice C. is CORRECT!
<em>TRUE... As the </em><em>catchall term</em><em> for </em><u><em>eukaryotic organisms</em></u><em> that are </em><em>not animals, plants, fungi</em><em>, or any single phylogenetically related group, it is not surprising that few characteristics are common to all protists.</em>
~~~
D. Protists are all <u>parasitic</u>.
The given statement in answer choice D. is (partially correct) FALSE.
<em>TRUE... </em><em>Many</em><em> protists are </em><u><em>pathogenic </em></u><u><em>parasites</em></u><em> that must infect other organisms to survive and propagate.</em>
<em>~~~</em>
Therefore, the correct answer choice is C.
I hope this was helpful! (✿◠‿◠)