Final answer:
Causal-comparative research compares different groups that have already been exposed to different conditions, while correlational research examines the relationship between variables without experimental manipulation.
Step-by-step explanation:
In both causal-comparative and correlational research, there is a focus on identifying relationships between variables. However, the two methods differ in terms of their approach. Causal-comparative research compares different groups that have already been exposed to different conditions, while correlational research examines the relationship between variables without experimental manipulation. Therefore, the correct answer is A. rely on the same research procedures