Numbers, numbers everywhere

Today's quiz is brought to you by the publishers of all the textbook supplements.

I am so confused in law school right now because?
(a) - U.S.C., Title 28 (pick a section, any section)
(b) - Rule 4
(c) - UCC § 2-207
(d) - Bluebook, T-1
(e) - all of the above

Please feel free to leave your vote in the comments. If you have no idea what I'm talking about, vote anyway. The answer is fairly obvious.