Because all those energy sources are natural and will always be there, when ever there is a need for extra energy.
1.
Paramecium
2.
Amoeba
3.
Paramecium
4.
Euglena
5.
Volvox
6.
Amoeba?
7.
Amoeba
8.
Cilia
9.
Flagellum
10. Psuedopods
11. Flagella
12. Euglena
(Chloroplast)
13. Amoeba
14. Euglena
15. Paramecium
16. Paramecium
17. Amoeba
18. Volvox
I hope this is all correct!
Option 1 is the correct answer
