Just to throw it out there, earlier in this section 47-1-21- there is another parallel flaw question where the correct AC has two subjects instead of one, like the stimulus. However, it is correct since it was the only AC with the actual flaw.
I guess if you arrived at the ACs and saw two with the same flaw as the stimulus, then you get picky on those other details. But we have to find the flaw first.
I picked (C) on this one as well BTW, so not trying to preach
EDIT: BTW, I think this is a great example of the LSAT throwing out an attractive answer earlier on, so that when we read the other ACs (which probably contains the correct answer, in this scenario) since we already found something attractive we let our mental faculties slip and flippantly reject the other ACs without really reading what they say- "two subjects- NEXT!" which is what I did because I liked (C). Most likely with tricker questions, they are priming the pump for this to occur, especially later in the section when we are getting tired.