Garrod Hypothesized That Inherited Diseases Such as Alkaptonuria,the Inability to Metabolize

Garrod hypothesized that inherited diseases such as alkaptonuria,the inability to metabolize the chemical alkapton,occur because

A) metabolic enzymes require vitamin cofactors,and affected individuals have significant nutritional deficiencies.
B) many metabolic enzymes use DNA as a cofactor,and affected individuals have mutations that prevent their enzymes from interacting efficiently with DNA.
C) certain metabolic reactions are carried out by ribozymes,and affected individuals lack key splicing factors.
D) genes dictate the production of specific enzymes,and affected individuals have genetic defects that cause them to lack certain enzymes.