Answer:
I: ABDC; Group
II: BCAD; Group
III: CDBA; Group
IV: DACB Group
Explanation:
Incomplete counterbalancing is an experimental design that controls for order effects by using a limited number of possible sequence of treatments administered in such. Way that each treatment appears equally often in each position. As seen in the answer chosen above, experiment A,B,C and D all appeared in the four available positions.