Which of the Following Statements Describes an Evaluative Study

Which of the following statements describes an evaluative study?

A) This study examined the differences in improvement in reading readiness scores for two groups, one of which had received the prekindergarten readiness service and one of which had not received this service.
B) This study examined the relationship between age and improvement scores for a client group in order to examine whether age is a predictor of improvement for our clients.
C) This study asked each client to indicate if they needed a given service when offered a list of services offered by the agency.
D) This study collected data on the variables of stress and stressors in order to examine the relationship between these two variables.