The question asks about the study of drug interactions with target molecules through binding interactions. This is a topic within the field of pharmacology that specifically deals with understanding how drugs exert their effects on the body by interacting with specific molecular targets.

Let's analyze the options:

1. Pharmacology: This is the broad study of drugs and their effects on living organisms. While it encompasses a wide range of topics, it does not specifically focus on the binding interaction aspect.
2. Pharmacokinetics: This branch deals with the movement of drugs within the body, covering aspects like absorption, distribution, metabolism, and excretion. It does not focus on the binding interaction.
3. Pharmaco dynamics: This branch of pharmacology specifically studies the effects of drugs on the body and how they produce their effects through interactions with biological targets. It involves understanding how drugs bind to their target molecules and initiate a biological response.
4. Pharmacophore: This is a concept in drug design which refers to the abstracted features of a molecule responsible for interactions with a specific target, not the study of interaction itself.

Conclusion: The correct answer is Pharmaco dynamics as it specifically deals with how drugs interact with target molecules through binding to exert their effects.