The correct answer is B. A bathroom sink.
When considering where you are allowed to wash your hands, the most appropriate option is a bathroom sink (B) because it is specifically designed for personal hygiene, including handwashing.
Here’s why the other options are generally not advisable for handwashing:
A. A service sink: Service sinks are typically used for tasks like cleaning and disposing of waste or dirty equipment, not for personal hygiene.
C. A food preparation sink: This type of sink is designated for washing foods or food-related items and should not be used for handwashing to avoid contamination.
D. A three-compartment sink: This sink is primarily used for washing dishes and kitchen equipment. Handwashing should not be done here because it can lead to cross-contamination.
Thus, the bathroom sink is the most suitable and hygienic option for handwashing.