o na

When a person asks or says something obvious so you reply with o na. Like why would you ask that thats so obvious. Can also be used to say yes to what they are saying. Can also be used with other terms like "O na guys" "lol o na" OOO NA GUYS"

Did the towers fall on September 11 2001?
"O NA GUYS"
Yo are you coming over today?
"o na"