Aresearcher is asking managers and line workers questions such as what type of problems they experience, where they are most likely to experience them, who is responsible for them, and how the problems get resolved. asking these what, where, who, when, why, and how questions to get a better understanding of his client’s business decision-making situation is an example of using

Interrogative techniques.

Explanation:

The researcher in the given example is using 'interrogative techniques' to get a better understanding of his client's decision-making situation as the answer to these questions of what, where, who, when, why, and how questions would propose description that would reflect the skills of the client or his company. The researcher is inclined to know the thoughts or ideas more comprehensively and effectively to persuade the opposition to crack the deal. Thus, this kind of questioning demonstrates the example of 'interrogative techniques'.