Answer:
B
Explanation:
Answer B is correct:
Because the biologists are continuing to learn more and more about
such minute organisms, protozoan systematics – that is, the taxonomy (classification) and the evolutionary interrelationships of major groups of protozoa – remains a topic of debate and change, still today.
Some of the rather LARGE and <u>unwieldy taxonomic grouping</u>s of past years are particularly subject to revision with expansion of and refinement in the knowledge about the members of those – and related – assemblages. Paradoxically, the protozoa themselves are becoming more difficult to define with precision as our information about them and other microbial assemblages increases. Thus, presenting a single satisfactory circumscribed definition for them is not an easy task.
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Answer A sounds so funny.
Answer C and D are false because Protozoans are usually single-celled and heterotrophic.
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Hope this answer can help you. Have a nice day!