Question

Since each group depends upon the other groups. a. Fragment b. Run-on c. Correct

Answer 1

The answer is:  [A]: fragment .
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The phrase:  "Since each group depends upon the other groups."
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is NOT correct as it is — thus eliminating "Answer choice: [C]: correct" ; 
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and is NOT a  'run-on sentence' — thus eliminating
                                                  "Answer choice: [B]: run-on" .
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Rather, the phrase:
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 "Since each group depends upon the other groups."  ;
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  is a sentence FRAGMENT; which is the remaining answer choice given—  
"Answer choice:  [A]:  fragment" .
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