Final answer:
Sales Promotion is the most effective element of the promotional mix for a small grocery retailer to immediately increase purchases, as it provides short-term incentives that directly influence consumer behavior.
Step-by-step explanation:
For a small business grocery retailer trying to immediately increase purchases by customers, I would recommend Sales Promotion (B) as an element of the promotional mix. Sales promotions involve short-term incentives to encourage purchase or sale of a product or service, such as discounts, coupons, or a buy-one-get-one-free offer. These tactics can be implemented quickly and have a direct impact on consumer behavior, leading to increased foot traffic and immediate sales. Unlike advertising, which may take time to build awareness, or public relations, which focuses on building the brand image, sales promotion can drive urgent action. Personal selling could also be effective but may require more resources and time that a small grocery retailer may not have.