Question

what were the first life forms?
a single - celled organisms similar to protists
b single - cell organisms similar to bacteria
c simple organisms similar to small water insects
d simple organisms similar to small flies

Explanation:

The earliest life forms on Earth were simple, prokaryotic single-celled organisms, which are structurally and functionally similar to modern bacteria. Protists are eukaryotes, which evolved later, while insects and flies are complex multicellular organisms that appeared much later in evolutionary history.

Answer:

b. single-cell organisms similar to bacteria