Which Criminal History Purpose Code must be used by agencies for screening applications for firearms?

The correct choice for the Criminal History Purpose Code used by agencies for screening applications for firearms is the code F. This code is specifically designated for background checks related to firearm purchases and is part of the effort to ensure that individuals who are applying for firearms do not have disqualifying criminal histories.

This differentiation is important as other purpose codes serve different functions. For instance, codes like B and C might relate to other forms of employment screening or specific types of licenses that do not pertain directly to firearms. By utilizing the F code, agencies can comply with the relevant laws and regulations governing the sale and possession of firearms, ensuring that public safety is prioritized during the application process.