Answer:
Group
Step-by-step explanation:
The strongest form of proximity effect is achieved through the overlapping of the objects. However, the Grouping of the objects also provides a similar sort of proximity strength, and hence here group is the right answer. Through, grouping the required level of the proximity effect is being provided to the objects, and this is one part of the Gestalt principle of design. You should know that Gestalt principles can easily elevate a design, and that is why they are so popular in design.