Globalized evolution...... but I might be wrong
Answer: Option A) Oxygen may not have been able to accumulate in the atmosphere
Explanation:
Ozone, O3, is an allotrope of oxygen having three atoms in the molecule instead of the usual two present in molecular oxygen. Ozone is generated from oxygen, and is the only form in which oxygen can exist in the atmosphere.
Secondary succession has soil when primary doesn't
I don't know if this helps Sorry if it doesn't I tried