Your answer is Enamel it is the coating on teeth that helps prevent damage.
Answer:
The cell theory developed most quickly due to the invention of the microscope. Robert Hooke was the first scientist who saw cells in cork. After this discovery, a wide numbered of researches were made and cell theory was developed. The basic cell theory explained that how every living thing was made up of cells. After this, a lot of additions have been made in the cell theory and today the cell theory is known to have five basic postulates.
Most climate scientists agree the main cause of the current global warming trend is human expansion of the "greenhouse effect"1 — warming that results when the atmosphere traps heat radiating from Earth toward space. Certain gases in the atmosphere block heat from escaping.
Based on this exert, I'd say Option C