Answer:
Flat
Explanation:
The atlas is one of the two upper cervical vertebrae, also known as C1, which is the topmost vertebra of the spinal column. ... It is the vertebra that is in contact with the occipital bone, a flat bone located at the back portion of the head.
It IS NOT A because after a fire, soil remains, so it would be secondary, not primary. D is INCORRECT because after a volcano, only rock is left so it is primary succession, not secondary.
If you can post the picture I could tell you the correct answer.
Enzymes don't take part in a reaction but just speeds up a reaction