Researchers Studied Alcoholism Recovery, Comparing the Success Rate for Two

Researchers studied alcoholism recovery, comparing the success rate for two groups of participants: those receiving individual psychotherapy and those not receiving individual psychotherapy. The researchers measured sobriety once, at 18 months' posttreatment initiation. What study design would be most suitable for this type of research project?

A) Longitudinal descriptive design
B) Comparative descriptive design
C) Cross-sectional design
D) Model-testing design