The main purpose of subheadings are:
They stand out because of their size and attract attention.
The scanner will stop to read them and continue scanning until the next subhead which they'll then read.
Imperative
1) Indicative
2) Subjunctive
3) Indicative
4) Imperative
5) Indicative
6) Imperative
7) Subjunctive
8) Indicative
I think it's D, because that's how my teacher taught us.
Answer:
Air, water, noise, soil, light
