Final answer:
A 3-story multi-family building would fall under the LEED Homes and Multifamily Lowrise certification. This rating system is appropriate for buildings of 1 to 5 stories, making it the correct choice for the given scenario.
Step-by-step explanation:
The multi-family building in question, being 3 stories tall, would most accurately be classified under the LEED Homes and Multifamily Lowrise certification.
This certification is specifically designed for residential buildings that are 1 to 5 stories in height. Buildings higher than this range would typically fall under the LEED Multifamily Midrise category, which is for buildings that are between 5 and 9 stories tall. Options C and D, LEED BD+C: New Construction and LEED ID+C: Commercial Interiors, are not pertinent to this case as they refer to commercial and interior spaces, not residential multi-family buildings.