Re: electrophoresis, the inclusion of "Item 4" is definitely a data entry error that needs to be fixed.
Re: blotting, the statement you checked off is wrong in a couple ways. Antigen-antibody interactions are used in western blotting, but not in other forms of blotting (Southern blotting is for DNA & northern blotting is for RNA, and antigens/antibodies only apply to proteins), so that statement doesn't answer the question. Also, even when limited to western blotting, it wouldn't quite be correct to say that antigens are used to GENERATE antibodies...I mean, that's true in general but it's not like western blotting in reality is performed by letting B cells do their thing in the sample you're preparing. That is, antibody generation isn't really part of the blotting process itself, it's more of a prerequisite step.
For cerebral perfusion of the SNS, evidence varies -- an older article
suggests that the SNS does regulate cerebral blood flow, but a more recent review
suggests the opposite. From a scientific point of view, I'd be inclined to trust the more recent review, so we'll need to revise that question. Practically speaking, I have not often seen the MCAT test this aspect of the SNS one way or the other with any real frequency.
Finally, you answered the question on serotonin correctly, but the answer is coded incorrectly (another data entry error to fix). The idea is that you can promote the presence of serotonin in the synapse by either not letting it be taken back up (inhibiting the reuptake) or by not letting it be degraded.
Hope this helps, & thank you very much for the questions!