Final answer:
According to NEC guidelines, a kitchen island counter space measuring 48 inches by 24 inches requires at least one receptacle. Additional receptacles are necessary for each additional 48 inches of counter space, but in this case, the length does not exceed 48 inches, so only one receptacle is required.
Step-by-step explanation:
The question asks how many receptacles are required for a residential island counter space measuring 48 inches in length and 24 inches in width. According to the National Electrical Code (NEC), which provides guidelines for electrical installations, there are specific requirements for the number of receptacles based on the counter space provided.
In this case, the NEC requires that a kitchen countertop or work surface that is 12 inches or wider must have at least one receptacle outlet. Furthermore, for island countertops or work surfaces, at least one receptacle is required for each side of the island that is larger than 12 inches in length. However, if the countertop is longer than 24 inches, more than one receptacle may be necessary. The requirement states that for every additional counter space of 48 inches in length or fraction thereof, you must add a receptacle.
Given that the counter space in question is 48 inches long, we would initially need one receptacle for compliance. But since the length does not exceed 48 inches, only a single receptacle is necessary. Thus, the answer is (a) 1 receptacle.