If each booth must be adjacent to another of the same product, how should the arrangements be organized?

The correct choice emphasizes the requirement that each booth must be adjacent to another booth of the same product. Organizing the booths in pairs before arranging the rest is a strategic approach that acknowledges this adjacency condition. By initially pairing the booths that are selling the same product, you ensure that they are grouped together in accordance with the specified requirement.

This method allows for a systematic arrangement where each pair can then be positioned relative to other pairs or different groups of products later in the arrangement process. The focus on pairs emphasizes that adjacency is crucial, which aligns perfectly with the condition laid out in the question.

The other options do not adhere to the condition of adjacency for the same product. Random arrangements would violate the requirement entirely, and unique identifiers do not address the adjacency issue. Similarly, grouping by product type does not guarantee that each booth of the same product is next to its counterpart. Hence, the best approach to satisfy the condition is to arrange them in pairs initially.