To create a market-product grid for bed pillows, the most effective way to segment the market would be using
A. the age of the sleeper: less than 18 years of age, 18 to 44 years of age, or 45 years and older.
B. the sleeper's annual income: less than $25,000, $25,000 to $49,999, or $50,000 and over.
C. the sleeper's gender: male or female.
D. the time of sleep: day or night.
E. how the sleeper sleeps: side, back, or stomach.
Answer: E. how the sleeper sleeps: side, back, or stomach