Final answer:
Ibuprofen is a good choice for pain control in primary dysmenorrhea because it inhibits the synthesis of prostaglandins, which are chemicals that promote inflammation and pain.
Step-by-step explanation:
Ibuprofen is a good choice for pain control in the case of primary dysmenorrhea because it belongs to a class of medications known as nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs, including ibuprofen, work by inhibiting the synthesis of prostaglandins, which are chemicals in the body that promote inflammation and pain. By reducing prostaglandin levels, ibuprofen helps to alleviate pain associated with primary dysmenorrhea.