George Is Conducting a Research on the Effectiveness of a New

George is conducting a research on the effectiveness of a new counseling technique in improving the career orientation of participants. Due to the availability of participants and the absence of cases where urgent treatment intervention was needed, there were no issues with the random assignment of participants to treatment groups. George wants to distinguish the effects of the treatment from effects due to client expectations, attention, and other nonspecific aspects. Which of the following control groups is best suited to his cause?

A) Waiting-list control group
B) Delayed-treatment control group
C) Placebo control group
D) Matched control group