Answer:
B. A cross-sectional study.
Explanation:
Observational studies include the observation of the effects of risk factors, diagnostic examinations, treatment or other intervention by the researchers in order to measure certain outcomes.
A cross-sectional study also known as transverse study or prevalence study is a sub-branch of observational study that involves the analysis of data(cross-sectional data) from the population or a representative subset at a precise point of time. Thus, <em>the problem statement provided here illustrates the cross-sectional study as it observes and analyzes cross-sectional data. </em>
Robert Walton<span> is the captain of a ship traveling to the North Pole. </span>Walton<span> is searching for a Northern passage to the Pacific, and </span>his attitude<span> is one of determination. He is determined to accomplish "some great purpose."</span>
