Ash can be harmful to an environment. It mostly depends on how much ash there is though. If a volcano erupted such as Mt. St. Helen's then yes that can harm an environment. Ash can cover the sky and block out the sun for days before disappearing and that will affect the life of plants
I believe the answer is A hope this helps :)
1.formation of glucose, which leaves the chloroplast
2.formation of a stable 3-carbon compound
3.formation of an unstable 6-carbon compound
4.use of ATP to form a high-energy 3-carbon compound