What are pharmaceuticals primarily used for?

Pharmaceuticals are primarily used for diagnosing, treating, or curing diseases, which is an essential function in healthcare. They encompass a wide range of compounds that can influence biological systems and may include various forms such as medications and vaccines. These substances are designed to interact with specific targets in the body, such as enzymes, receptors, or pathogens, with the ultimate goal of improving health outcomes.

While the other options involve important functions in their respective fields, they do not pertain to the primary purpose of pharmaceuticals. Enhancing agricultural productivity relates more to agrochemicals and biotechnology applications in farming. Creating laboratory equipment focuses on the tools used for research and experimentation rather than the therapeutic use of drugs. Conducting forensic investigations involves techniques and technologies associated with legal and crime scene analysis but does not directly involve pharmaceuticals in their conventional role. Therefore, the primary use of pharmaceuticals remains centered on health-related applications, making the correct answer clear.