Final answer:
According to the NFPA, a smoke alarm should be replaced after 10 years from the date of manufacture.
Step-by-step explanation:
The National Fire Protection Association (NFPA) recommends replacing a smoke alarm after 10 years from the date of manufacture. This is because the components of the smoke alarm, including the sensor, batteries, and electronics, may deteriorate over time and affect the alarm's effectiveness. It is important to regularly check and replace smoke alarms to ensure they are functioning properly and providing reliable protection.