Which of the Following Statements About Genes Is TRUE

Which of the following statements about genes is TRUE?

A) Each gene controls the development of a single characteristic or trait.
B) Like a massive computer program, an organism's inherited genetic makeup directs its development and behavior from infancy through old age.
C) Genes direct the manufacture of proteins, the building blocks of all body tissues and structures, and they are activated in different cells in the body at different times.
D) An organism's phenotype and genotype are essentially identical, except for rare cases of gene mutations.