were single-celled. had organ systems. were multi-cellular. had small appendages.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Fossil records indicate that Earth was first inhabited by bacteria-like organisms. These organisms
Possibilities:
- were single-celled.
- had organ systems.
- were multi-cellular.
- had small appendages.

were single-celled.