Final answer:
A cross-sectional study on obesity and watching television would likely find an association between these two variables at a single point in time, but cannot confirm causation.
Step-by-step explanation:
A cross-sectional research study examining the association between obesity and watching television is most likely to reveal b) Association between two variables at one point in time. Such a study collects data from a sample of subjects just once, aiming to identify potential relationships between variables observed. However, it is important to note that while cross-sectional studies can indicate correlation, they do not imply causation. This means that although the study could show that obesity levels are related to how much television is watched, it cannot conclude that watching television is the cause of obesity. For establishing causation, more rigorous methods such as controlled experiments are necessary.