A group of climbers ascends a narrow , snowy mountain ridge .
Chances are about even that a group of climbers makes their way to a rest stop on a mountain ridge .
Chances are about even that a group of climbers makes their way to a rest stop on a mountain ridge .
It is impossible that a group of climbers makes their way to a rest stop on a mountain ridge .
A group of climbers makes their way to a rest stop on a mountain ridge .