The correct answer is A. Combine longitudinal and cross-sectional research strategies
Explanation:
Cross-sequential design is a type of design in research that focuses on studying groups of people over a period of time. For example, through this design, you can analyze the development of skills in a sport by observing groups of people of different ages over many years. Additionally, this type of research emerges from the combination of two other models, the first one is the longitudinal research that studies a few subjects over a long time, while the second one is a cross-sectional study that studies multiple subjects in a specific moment. Thus, this model allows researchers to "combine longitudinal and cross-sectional research."