Final answer:
Ibuprofen is the NSAID among the provided options. NSAIDs inhibit the synthesis of prostaglandins that cause inflammation and pain by targeting the COX enzyme, and ibuprofen is available over the counter.
Step-by-step explanation:
The provided options is a nonsteroidal anti-inflammatory drug (NSAID). The correct answer is a) Ibuprofen. NSAIDs are a class of drugs that provide analgesic (pain-reducing) and antipyretic (fever-reducing) effects and, in higher doses, anti-inflammatory effects without the negative effects of steroids. NSAIDs work by inhibiting the conversion of arachidonic acid into prostaglandins, which are compounds that cause inflammation and pain. Ibuprofen does this by binding to the cyclooxygenase (COX) enzyme, which is necessary for prostaglandin synthesis. Popular over-the-counter (OTC) NSAIDs include ibuprofen and naproxen, with brand names like Advil, Motrin (ibuprofen), and Aleve (naproxen). It is important to note that aspirin is also an NSAID, but it works slightly differently by deactivating COX with an acetyl group. Other options provided in the question such as Isosorbide dinitrate, Nifedipine, and Apap (which is acetaminophen and not an NSAID) do not have this action.