Of the Following, Which Describes a Likely Causal-Comparative Study

Of the following, which describes a likely causal-comparative study?

A) Typical management procedures used by experienced teachers in a child-care setting
B) Relationship between teacher job satisfaction and years of teaching
C) Differences in problem solving performance between children provided exposure to a computer training program and those who were not given the same exposure
D) Differences in acclimation to high-school between children from small and large middle schools