What approach focuses on personal interaction with customers to understand their preferences?

The correct approach that emphasizes personal interaction with customers to understand their preferences is selling. This method involves direct engagement with customers, where sales representatives or associates can ask questions, listen to feedback, and gain insights into what customers are looking for in products or services.

Through this interaction, sales staff can tailor their recommendations and create a more personalized shopping experience. This approach not only helps in meeting the immediate needs of customers but also builds rapport and trust, encouraging repeat business and customer loyalty.

While other options such as marketing research and customer service are also important in the broader context of understanding customer preferences, they do not focus as directly on the personal, one-on-one interaction that is characteristic of selling. Marketing research is primarily about gathering and analyzing data in a more structured manner, and customer service, while crucial, pertains more to assisting customers post-sale rather than engaging with them to understand their preferences in a proactive way. Retail management encompasses overseeing a store's operations and strategies, which may include selling techniques but is not focused solely on the personal interaction aspect.