a. first answer in photo.
b. A smoke alarm is critical for the early detection of a fire in your home and could mean the difference between life and death. Fires can occur in a variety of ways and in any room of your home. But no matter where or how, having a smoke alarm is the first key step toward your family's safety.
c. Install smoke alarms on every level of your home, inside bedrooms and outside sleeping areas. Test smoke alarms every month. If they're not working, change the batteries. Talk with all family members about a fire escape plan and practice the plan twice a year.