The standard for sprinkler installation in residential occupancies up to four stories is:

• A. NFPA 13R
• B. NFPA 13D
• C. NFPA 25
• D. NFPA 101

Answer: (A)

This question tests which sprinkler standard applies to residential occupancies up to four stories. NFPA 13R is the standard written specifically for low-rise residential buildings up to four stories and provides the design and installation requirements for sprinkler systems in homes, apartments, and similar dwellings with a focus on adequate protection while accommodating typical water supplies and simpler layouts. NFPA 13D covers one- and two-family dwellings and some attached units but is scoped for smaller residences, not buildings up to four stories in general. NFPA 25 deals with inspection, testing, and maintenance of water-based systems, not their installation design, and NFPA 101 is the Life Safety Code, which addresses overall life-safety requirements rather than the installation standard itself. Therefore, the standard for sprinkler installation in residential occupancies up to four stories is NFPA 13R.