When an agent acts for an undisclosed principal, the principal
will not be liable to third parties if the

(c) A principal, whether disclosed, partially disclosed, or
undisclosed is liable on contracts where the agent has actual or
apparent authority, or where the principal ratifies an agent’s contract. Actual authority includes express or implied authority
projected by the principal to the agent. Apparent authority of an
agent is authority perceived by a third party based on the principal’s
representations. Therefore, apparent authority can exist
only where there is a disclosed or a partially disclosed principal.
It follows, then, that an undisclosed principal will not be liable to
third parties if the agent acts outside the grant of actual authority.
Answer (a) is incorrect because when a principal ratifies a
contract it is liable for the terms of the contract. Answer (b) is
incorrect because when agents act with any type of authority,
then the principal is liable. Answer (d) is incorrect because
whether the principal tried to hide the agency relationship is
irrelevant to determine the principal’s liability. The critical issue
is did the agent act with some type of authority.