A source that provides information on the behavior, knowledge, and opinions of 16-year-olds regarding political matters and their ability to make informed decisions would be most relevant to the claim that the voting age should be lowered to 16. This source should provide evidence that supports the notion that 16-year-olds possess the necessary maturity and understanding to participate in the voting process effectively. A research study or survey specifically conducted on 16-year-olds' political engagement, awareness, and decision-making ability would be a suitable source for this purpose.
