Fossilized stromatolites A) all date from 2.7 billion years ago. ...

[penguins]

Fossilized stromatolites
A) all date from 2.7 billion years ago.
B) formed around deep-sea vents.
C) resemble structures formed by bacterial communities that are found today in some warm, shallow, salty bays.
D) provide evidence that plants moved onto land in the company of fungi around 500 million years ago.
E) contain the first undisputed fossils of eukaryotes and date from 2.1 billion years ago.

[Millan]

I know it's C, we did this last week

[penguins]

Thank you, thank you!!