Answer:
Option A. Bacteria.
Step-by-step explanation:
- It is presumed that, over millions of years of evolution, abiotic molecules evolved into the self-replicating molecules by means of natural selection.
- Cyanobacteria, or blue-green algae is a bacteria which was one of the oldest fossils found on earth. These microbes conduct photosynthesis: using sun light, water and carbon dioxide to produce carbohydrates and oxygen.
- Cynobacteria played a major role in forming oxygenated atmosphere.
- The first living things on the planet Earths was single-celled micro-organisms which lack a well defined cell nucleus were known as prokaryotes, and bacteria belongs to prokaryotes ans hence among given options bacteria matches the most for the first life form on earth.
Result: Among the given choices bacteria was most similar to first living things on earth.