Which describes the genetic code in a human?

a. different genetic codes appear in each different type of cell.
b. every human has the same exact genetic code.
c. genetic codes change frequently in reaction to external factors.
d. a genetic code determines the physical traits of the body.

     The right answer to this question is option D. A genetic code determines the physical traits of the body.

Explanation:

     What is known about the genetic code is that we have 4 different kinds of nucleotides, thymine, adenine, guanine and cytosine. There are more of them, but let's rely on these four for this question. These 4 nucleotides are the same on every living being on earth, what really changes is how they're organized on the protein making process. These proteins are going to be made based on the genetic code.

      After the explanation above, we can be sure that the genetic code determines physical traits of the body, and that's why every living being on earth have something in common, but at the same time, are not equal too.