Your brain is your best weapon. Understanding of the bears and knowledge of how to avoid them are with more than any weapon.

That said, if I need it, I vote for the close air support! I did encounter a bear in Alaska in 1982, but I was not alone, had a whole infantry company with me. That was when I learned that bears do not truly hibernate. This guy was HUGE, and smelled the hot food brought out to us in the field. It was late February and cold. He followed his nose and then realized he was inside our perimeter. We pulled everyone back and chased him out with grenade and artillery simulators. Not something I want to encounter in other circumstances.

We really thought that bears would not be a problem because they would be hibernating. Boy were we surprised.