Final answer:
Flashings, critical for preventing water entry, are used in roofs, windows, and chimneys but not typically in bathrooms, which use other waterproofing methods.
Step-by-step explanation:
Flashings are commonly used in construction to prevent water from entering a structure at joints or intersections. Flashing is a critical component for weatherproofing systems, and they are commonly installed in locations such as roofs, windows, and chimneys to direct water away from these vulnerable points. Flashings are not typically used in bathrooms as a primary function because bathrooms have different waterproofing requirements, such as tile backing and sealants to prevent water penetration. Therefore, the correct answer is C. Bathrooms.