What constitutes a breach of merchant privilege?

A breach of merchant privilege refers primarily to the rights and responsibilities a merchant has in relation to their customers and the conduct of business. In this context, detaining customers without consent is a significant breach because it violates a customer's personal rights and can lead to legal consequences. Merchants are granted the privilege to detain individuals suspected of theft or shoplifting, but this must be conducted in a lawful manner, ensuring the customer's rights are respected.

Failing to have agreements with tenants relates more to landlord-tenant laws and contractual obligations rather than merchant privilege. While it is essential for a merchant to have clear agreements with tenants for effective property management and legal protection, it does not directly pertain to the privileges afforded to merchants concerning customer dealings and interactions.

Wearing a uniform is more a matter of policy for appearance and branding rather than a legal issue tied to merchant privilege. Similarly, investigating unrelated thefts, while perhaps a practice within a retail setting, does not concern the rights and responsibilities associated with interacting with customers under merchant privilege.

Thus, the correct answer ties directly into the conditions surrounding how merchants can lawfully engage with and manage customer relations, particularly when it involves issues of consent and personal rights.