The correct answer is letter "B": You use information from a first sample for collecting a subsequent subsample for further study.
Explanation:
Multi-phase sampling is a strategy by which a large number of data under study is taken, then a subsample of that pool is taken, and after that, another smaller subsample is taken in an attempt to count with samples that best might represent the whole population. Usually, the process takes collecting two different samples, but it can be applied as many times as necessary.
