How old was Aisha (RadiAllahu Anha) at Marriage? Imam Uthman Vs Catholic man

A Catholic man came to argue about the age of Aisha (RadiAllahu Anha) marriage to prophet Muhammad (peace be upon him). Sheikh Uthman Ibn Farooq discussed this matter with him in a nice & friendly way even though he was little rude.

http://https://www.youtube.com/watch?v=wULw15M4Kj8&t=217s