Which of the following is a form of sales promotion?

A form of sales promotion is "offering free samples to customers." This is a marketing technique used to encourage potential customers to try a product or service by giving them a small amount of it for free. By providing customers with free samples, businesses hope to generate interest and positive word-of-mouth about their products, which can lead to increased sales. Additionally, free samples can be a way for businesses to introduce new products to the market and get feedback from customers. Therefore, the correct answer is "offering free samples to customers."