The correct option is C Gene regulation theory
The genetic theory of aging or Gene regulation theory states that lifespan is largely determined by the genes we inherit. According to the theory, our longevity is primarily determined at the moment of conception and is largely reliant on our parents and their genes.Hence Ageing is an intrinsic phenomenon which is controlled by some genes was illustrated by the theory of Gene regulation theory.
So, the correct answer is 'Gene regulation theory'.