Acetaminophen is effective in reducing which of the following symptoms?

Acetaminophen is primarily known for its analgesic (pain-relieving) and antipyretic (fever-reducing) properties. It is effective in alleviating pain associated with various conditions, including headaches. This medication works by inhibiting certain pathways in the brain that signal pain, thus providing relief from headaches, which are often caused by tension, migraine, or other factors.

While acetaminophen is commonly used for headaches, it is not classified as an anti-inflammatory medication, which is crucial in understanding its limits. It does not effectively treat inflammation, which distinguishes its use from other medications like nonsteroidal anti-inflammatory drugs (NSAIDs). Therefore, the answer is accurate in stating that acetaminophen is effective in reducing headaches, while other options incorrectly suggest limitations to muscle pain or inflammation.