Which drug is indicated for pain related to acute renal calculi?
Narcotic analgesics are usually needed to relieve the severe pain of renal calculi.

Options B and D: NSAIDS and salicylates are used for their anti-inflammatory and antipyretic properties and to treat less severe pain.
Option C: Muscle relaxants are typically used to treat skeletal muscle spasms.
Narcotic analgesics
Nonsteroidal anti-inflammatory drugs (NSAIDS)
Muscle relaxants
Salicylates