Kumar is analyzing the reversal design of his intervention on the number of bites taken of non-preferred food items. He determines there is an immediate and consistent change in the data path when he introduces and removes the intervention, concluding the intervention he implemented produced the change in behavior. Which type of analysis is Kumar conducting?
a) Across-phase formative visual analysis
b) Summative visual analysis
c) Within-phase formative visual analysis
d) Statistical analysis