According to Standard V(A) - Diligence and Reasonable Basis, CFA members are not required to develop or co-develop a quantitative model themselves (Option A) nor become experts in every technical aspect of the model (Option B). Instead, they must understand the assumptions and limitations inherent in any model used, as well as how the model's results inform decision-making. This ensures that members can critically evaluate the model's applicability and reliability in their investment research. The correct answer is C, as it aligns with the requirement to comprehend the model's foundational aspects without needing technical mastery.