How do scientists think protobionts formed?

a. cell-like structures formed from molecular bubbles.

b. prokaryotes absorbed other prokaryotes.

c. archaea reproduced with bacteria.

d. eukaryotes evolved due to natural selection.

The correct answer is A.

Explanation:

The very primitive and early microorganisms on the earth's surface were protobionts.

Protobionts are cell-like microscopic structures, and they are made up of organic and inorganic molecules present in a lipid bilayer membrane. The layers of the lipid membranes were folded into bilayers and transformed into a bubble shape when placed in water.

These membranes were selectively permeable and also observed shrinkage and swelling in osmotic conditions. Protobionts also possess the characteristics of reproduction.

d. planting trees

the trees take in carbon to make oxygen.