Final answer:
The authority of an agent is provided by the principal, not by customers, lenders, or other parties involved in a transaction.
Step-by-step explanation:
The authority of an agent is provided by the principal. This fundamental principle of agency law means that the agent's ability to act on behalf of the principal, such as entering into contracts or making representations, stems from the consent and authority granted by the principal.
In the context of financial capital markets, a bank providing a loan might require a borrower to provide income information and undergo a credit check, involve a cosigner, or require collateral as additional security measures. However, these practices do not directly relate to the authority of an agent but rather to the security of the loan.