Answer: billions of types of proteins
Since we were given only one point, we have to test each exponential function for the point

Since exponential functions are of the form

, The correct option is between option A and option C.
For option A,

On substitution, we have;



.
Since the point satisfied the exponential function

, the exponential function goes through it.
Hence the correct answer is option A.
No need to test for option C again.
Answer:
Aluminum
Explanation:
The density of Aluminum is 2.7 g/cm3
We know the volume and mass of the unknown metal, as density is mass/volume: 81g/30cm3 = 2.7 g/cm3 which is the density of Aluminum :)
Plastics clearly constitute an important component of the range of materials used in modern society. Almost all aspects of daily life involve plastics or rubber in some form or the other. ... Owing to their light weight, plastics reduce transportation costs and, therefore, atmospheric carbon dioxide emissions./Plastic is durable and provides protection from contaminants and the elements.