What is formed by the interaction of lightning with oxygen?

carbon dioxide

nitrogen

water vapor

ozone

You have to have a chemical on the left in order to have it in a different form on the right. So go down your list.

Here's the actual equation

O2 + Energy (lot's of) ===> produces something on the right.

The only thing you have on the left is oxygen.

Carbon Dioxide is made how? There's no carbon on the left.

Nitrogen? How did that come into the picture. There's no Nitrogen on the left.

Water? I don't think so. There's no hydrogen on the left.

By elimination all that is left is Ozone. But what is Ozone? It's chemical formula is O3. It's the stuff that makes the air small so fresh after a rainstorm.

3O2(g) ===>  2O3 (g)

D

b.

developed countries have tended to improve the environment, while developing countries have tended to damage it.