; (B) the methodology that was used to collect such information; (C) the degree to which financial institutions provided information requested; (D) why such information is not sufficient to develop the advisory described in subsection (a); and (E) any barriers to obtaining the information that is required to develop the advisory described in subsection (a). (c) Rulemaking FinCEN shall, not later than 3 months after the date of the enactment of this section, after consulting with the Director of the Federal Bureau of Investigation and the head of the Bureau of Alcohol, Tobacco, Firearms and Explosives at the Department of Justice, define by rule the following terms for the purposes of this section: (1) Firearm accessory. (2) Homegrown violent extremist. (3) Lone wolf. (4) Lone actor. (d) Definitions For the purposes of this section: (1) Domestic terrorism The term domestic terrorism has the meaning given the term in section 2331 of title 18, United States Code. (2) FinCEN The term FinCEN means the Financial Crimes Enforcement Network. (3) Financial institution The term financial institution has the meaning given the term in section 5312(a) of title 31, United States Code. (4) Firearm The term firearm has the meaning given the term in section 921(a) of title 18, United States Code.