Final answer:
Heroin is challenging to isolate and analyze in the body because it is metabolized into another substance. Drugs undergo biotransformation processes like oxidation and conjugation, changing their chemical properties and making detection harder. Hence, option (c) is correct.
Step-by-step explanation:
Many drugs like heroin are often difficult to isolate and analyze in the body because it is metabolized into another substance in the body. Heroin and other drugs can have a very rapid onset of action, particularly when injected intravenously, and they begin to interact with the body's systems immediately upon entry. Once in the bloodstream, these substances reach their target organs, such as the brain, and begin to exert their effects.
Heroin, for instance, produces intense euphoria due to its action on the brain. However, as the body begins to process the drug, it undergoes metabolic transformations, often in the liver, converting it into other compounds. This metabolic process is known as biotransformation, and it involves reactions such as oxidation, reduction, hydrolysis, and conjugation. These transformed substances can be more difficult to detect and analyze than the original drug because they might have very different chemical properties and may be present in lower concentrations.