By studying genetics, scientists have learned that control how organisms develop.
a. phenotypes
b. bacteria
c. genes
d. genotypes

C. genes

Explanation:

Genes are basic physical & functional unit of heredity. Genes are made up of DNA or we can say that they are segments of DNA which have instructions to synthesize bio molecules known as proteins and these protein molecules are further responsible for characteristics of an organism. Genes are located at a specific location in our chromosomes and the location is known as locus. Almost all the characteristics which an organism has depend upon the kind of information they have in their genes.

During developmental stages, how an organism will develop totally depends upon what kind of proteins are being synthesized at that time and as already explained, protein synthesis totally depends upon type of genes present in the organisms.

The answer is C. genes

Explanation:

Genes are the storage units of genetic information in a locus of deoxyribonucleic acid (segments of DNA) that contain information on how the body's cells should function and their development. The genes have elements that indicate where to read, and their content determines the composition of the proteins that are formed. Genes are the molecular unit of genetic inheritance, because it stores genetic information and allows it to be transmitted to offspring.