Question 1 (1 point) Supermart Inc. operates 151 stores. Cathy Ng, Marketing Manager, feels that the level of lighting may affect store sales. She chooses three levels of lighting (soft, medium, and bright) and randomly assigns 10 stores to each lighting level. Cathy's experimental design is a _ _ _. O a) completely randomized design O b) normalized block design O c) random block design O d) factorial design O e) fractional design