Answer:
A. Nonequivalent control group
Explanation:
The research design described, where the administrator compares tardiness records between a school with no lockers and a school with lockers, is best categorized as Nonequivalent control group
In a nonequivalent control group design, the researcher compares groups that were not randomly assigned and therefore may differ in important ways. In this case, the two schools (one with lockers and one without) are compared, but there is a lack of random assignment which could lead to potential differences in the groups aside from the presence of lockers.