Final answer:
The official name of a drug is Ibuprofen, which is a nonsteroidal anti-inflammatory drug (NSAID) used for pain relief and reducing inflammation. Placebo and Pain reliever are not specific drug names.
Step-by-step explanation:
The official name of a drug can vary depending on its chemical composition and the brand or generic name it is marketed under. In the given options, 'Ibuprofen' is the official name of a drug. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) commonly used for pain relief and reducing inflammation. It is sold under various brand names, such as Motrin and Advil. Placebo is not the official name of a drug, but refers to a substance with no therapeutic effect. Pain reliever is a general term for drugs used to alleviate pain, but it is not the specific name of a drug.