Answer: In such situation Don's Fashions could conduct market research to validate their target market.
Explanation: It's given that Don’s Fashions is noticing a downward trend in sales. The company has been reaching out using social media to connect with customers which they define as “fashion forward consumers between the ages of 15-30.” However, lately it seems that very few people are responding to the social media promotions.
Therefore at this particular stage they can decide to conduct a thorough market research to validate their target market and see it their marketing and strategies have been able to penetrate the market they were targeting.