4. The response time (in milliseconds) of twenty subjects was recorded when they were asked to recognize a figure of a certain shape (circle, triangle, or square) and color (red or blue). Each participant was shown all 6 figure combinations. What was the design of the study?

a. Two-way mixed ANOVA b. Two-way repeated-measures ANOVA c. Three-way mixed ANOVA d. Analysis of Covariance