Final answer:
The company is using an a priori segmentation approach by dividing the market based on predefined usage rates such as nonusers, light users, or heavy users of deodorants.
Step-by-step explanation:
The company is using an a priori segmentation approach. This method divides the market into segments based on predefined criteria, such as usage rate, which in this scenario includes nonusers, light users, or heavy users of deodorants. Unlike post hoc or a posteriori segmentation, which is based on actual consumer behavior or characteristics identified after research, a priori segmentation relies on assumptions or simple criteria to define segments before any research is conducted. This type of segmentation is common when entering new markets or product categories as it provides a strategic starting point for targeting consumers.