Final answer:
Inventory control is vital for close management of products in a salon, optimizing stock levels and procurement processes, but it is not related to supplier discrimination or the ignoring of customer feedback.
Step-by-step explanation:
The element vital for allowing close management of products purchased for retailing in the salon is B. Inventory control. This process is crucial because it helps in tracking the products on hand, determining when to reorder, and analyzing product performance. Good inventory control can prevent overstocking or stockouts, optimize the procurement process, and ensure that products that are in demand are always available.
On the contrary, options such as A. Discriminating against certain suppliers, C. Ignoring customer feedback, and D. Bulk purchasing, do not directly facilitate close management of inventory. Bulk purchasing might help in cost savings but doesn't pertain to management post-purchase. Customer feedback is critical for understanding product popularity and improving the selection, while supplier discrimination is both unethical and unhelpful in inventory management.