What characteristic makes a substance a mineral?

it is found in certain rock strata.
it is a liquid, solid, or gas.
it has a crystal structure.
it is only an organic compound.

It has a crystal structure.

Explanation:

Minerals occur naturally and are generally common and are defined by several factors. They are crystalline inorganic compounds, this means that their structures are made up of orderly, repeated atoms in a regular geometric arrangement, and they are not comprised of living things. These compounds are solid at room temperature and often made from natural geologic processes. Furthermore, their structures are comprised of a definite chemical compound and their atomic ratios stay the same.

Hope it helps!

Explanation:

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides

i believe your answer would be c.. : )