The correct option is
B Relieve pain
Analgesic drugs are pain killers. They are used to relieve pain. They act on central and peripheral nervous system. There are many group of analgesics such as simple analgesics (paracetamol and aspirin), non-steroidal anti inflammatory drugs (Ibuprofen and Naproxen Sodium) and opioids (morphine, pethidine). These drugs are sold under medical prescription and their long term use can develop tolerance in the body due to which the effectivity of drugs is used.
So, the correct answer is 'Relieve pain'.