In addition to 10% of devices not affected, what else must be tested when site-specific...

Whensite-specific software(such as logic for fire alarm control panels) is changed,100% of the devices affectedby that change must be tested to confirm correct operation. Also,10% of unaffected devicesmust be tested as a safeguard.

NFPA 72 (2022), Section 14.4.2.2.4:

“When system software is modified, 100% of the affected devices or functions and 10% of the nonaffected devices or functions shall be tested.”

This ensures that updates don’t unintentionally compromise unrelated areas of the system.

Correct answer: D. 100% of devices affected