What is the difference between user$-$interface designers and traditional ethnographers?

None of the other choices is correct.

User$-$interface designers focus on interfaces for the purpose of changing and improving them, whereas traditional ethnographers are just interested in understanding their subjects.

User$-$interface designers often need to immerse themselves in cultures for weeks or months, whereas traditional ethnographers typically limit the process to a shorter period of time.

User$-$interface designers do not have to understand their subjects, where traditional ethnographers do$.$