CLEAN : Matthew McConaughey urges 'gun responsibility' at White House podium

The video discusses the tragic story of Alethia, a young victim of a shooting, and the broader issue of gun responsibility. It highlights the emotional impact on the community and calls for nonpartisan action towards responsible gun ownership, including background checks, raising the minimum age for purchasing certain firearms, and implementing red flag laws.

What does the speaker mean by a 'window of opportunity' in the context of gun responsibility?

What specific age is suggested for raising the minimum purchase age for an AR15 rifle?