The correct statement is:
The relationship between independent variable A and dependent variable C, and the relationship between independent variable B and dependent variable C can both be analyzed, but they must be analyzed using separate scatterplots.
In a scatterplot, each independent variable can be plotted against the dependent variable to examine their individual relationships. However, combining both independent variables in a single scatterplot would be inappropriate if you want to analyze them separately, as it could create confusion and obscure the individual relationships.