A - incorrect, the two clauses in the sentence are not logically related to each other and thus this sentence is a run-on(What’s a run on ---> 'them' in choice a is a big big BIG error that should jump out and scream at you.
namely, that sentence is a 'comma splice': a sentence in which two independent clauses (i.e., sentences that can stand on their own as complete sentences, not subordinated to any other main clause) are joined together by a comma. that phenomenon, which creates one type
...
namely, that sentence is a 'comma splice': a sentence in which two independent clauses (i.e., sentences that can stand on their own as complete sentences, not subordinated to any other main clause) are joined together by a comma. that phenomenon, which creates one type
...






