Answer: seek to discover words that offer sophisticated ways to describe local cultural realities.
Step-by-step explanation:
Focal vocabulary refers to the words associated with concepts that are important in a specific culture, so an investigation that attempts to identify words that are used to describe the cultural reality of a community would be the most suitable to examine the focal vocabulary.
Genetic evidence wouldn´t be relevant in such a study, as linguistic anthropology is centered on the interaction of language and culture.
The origin of their syntax and grammar, how they are different from other communities, and the relationship between dialects and where they live wouldn´t be relevant to an investigation on focal vocabulary.