Of all of the amino acids only 9 are essential and .

can only be obtained from the food you eat
can only be found in protein supplements
can be found in vitamin supplements
are found normally in the body and not needed in part of the diet

can only be obtained from the food you eat.

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation:

igneous rocks which formed by the crystallization of magma at the surface of the earth called extrusive rocks. they are characterized by fine-grained textures because the rapid cooling at or near the surface did not provide enough time for large crystals to grow.