The inequality representing the condition that there must be fewer than 12 visitors in each tour group is n < 12.
The question presented by the student involves understanding and writing an inequality to represent a condition - in this case, the restriction of having fewer than 12 visitors in each tour group.
The inequality that correctly represents the number of visitors, n, allowed in a tour group is n < 12. This inequality signifies that the number of visitors must be less than 12 to comply with the group's limit.