What concession is described when manufacturers sell to off-price merchants on the condition that they operate far from traditional retailers?

The question describes a scenario where manufacturers and designers sell products to off-price merchants with a specific condition: that these merchants operate far from traditional retailers. This condition directly relates to the physical placement or location of the retail outlets. Manufacturers impose such conditions to avoid direct competition with their full-price retailers and to maintain brand image and pricing integrity.

• a) Location of the retail outlets: This option directly addresses the condition mentioned in the question, which specifies that off-price merchants must operate "far from traditional retailers."
• b) Unconditional purchasing: This is incorrect because the question explicitly states a "condition" for selling.
• c) Promotional considerations: This refers to advertising and marketing efforts, not the geographical placement of stores.
• d) Retailer's ownership: This refers to who owns the retail business, which is not the condition described.

Therefore, the concession applicable is related to the location of the retail outlets.

The correct option is a).

The final answer is $\boxed{\text{a. Location of the retail outlets}}$