Rearrange the events into chronological order. Place the first event to occur at the top and the last event to occur at the bottom. Gases from Earth's surface form the atmosphere.
Earth's surface cools.
Photosynthetic organisms absorb atmospheric carbon dioxide and release oxygen.
Organisms with aerobic metabolism evolve.
The composition of Earth's atmosphere changes.

what subject is this

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.

a physical change is being made.

the answers are a and c