Help please

In which environment would primary succession occur? a forest with a few remaining trees after a recent wildfire an area of exposed rock after a glacier melts away beach that is exposed to the air at low tide an abandoned baseball field in a small town

Consider the story you just read. all but one of the choices below indicate that something is living.

Rank the four gases (air, exhaled air, gas produced from from decomposition of h2o2, gas from decomposition of nahco3) in order of increasing concentration of co2