Answer:
C) 2 x 2 mixed factorial
Explanation:
A 2 x 2 mixed factorial design refers to a research study that uses 2 independent variables (can be more, e.g. 3 x 3). One of the variables is a within-subjects factor, in this research the flavor is the within-subjects factor. The other variable is a between-groups factor, the between-groups in this research are the two groups of participants.