Which of the Following Statements About Smoke Detectors Is MOST

Which of the following statements about smoke detectors is MOST accurate?

A) Smoke detectors initiate an alarm much slower than heat detectors.
B) In most cases, smoke detectors are installed in nonresidential and large multi-family occupancies.
C) Smoke detectors are self-contained units capable of both detecting smoke and sounding an alarm.
D) Typically, smoke detectors are installed in single-family residences and smaller multi-family occupancies.