Which of the following statements best describes pharmacodynamics?

• A. The study of how drugs reach their target in the body and how the levels of a drug in the blood are affected by absorption, distribution, metabolism and excretion.
• B. The study of how drugs can be designed using molecular modelling based on a drug's pharmacophore.
• C. The study of how a drug interacts with its target binding site at the molecular level.
• D. The study of which functional groups are important in binding a drug to its target binding site and the identification of a pharmacophore.