Task: songer_usc1sect

What follows is an opinion from a United States Court of Appeals.
Your task is to identify the number of the section from the title of the most frequently cited title of the U.S. Code in the headnotes to this case, that is, title 42. In case of ties, code the first to be cited. The section number has up to four digits and follows "USC" or "USCA".

ORDER
Respondents’ motion to dismiss is granted. An EPA notice of violation is not reviewable because it is not a final agency action. See 42 U.S.C. § 7607(b)(1983); Union Electric Co. v. Environmental Protection Agency, 593 F.2d 299, 304-06 (8th Cir.1979); West Penn Power Co. v. Train, 522 F.2d 302, 310-11 (3d Cir.1975); see also Air California v. United States Department of Transportation, 654 F.2d 616, 620-21 (9th Cir.1981) (FAA letter warning of possible civil penalties not reviewable as non-final).

Question: What is the number of the section from the title of the most frequently cited title of the U.S. Code in the headnotes to this case, that is, title 42? Answer with a number.
Answer:

Answer: 7607