Final answer:
Diet Coke is least likely to be segmented according to stages in the family life cycle because it appeals to a broad demographic unrelated to specific family structures or life stages.
Step-by-step explanation:
The product that is least likely to be segmented according to stages in the family life cycle is d) Diet Coke. This is because Diet Coke targets a broad demography and is not tied directly to specific family structures or life stages.
In contrast, single-family homes, automobiles, European vacations, and General Electric appliances are typically marketed to consumers at different stages of their life, such as newly married couples, families with children, or empty nesters, reflecting their varying needs and financial capabilities as they progress through life.
Marketers recognize the importance of the family life cycle in identifying consumer trends and product segmentation.