What must be known by the principal at the time of ratification?

For ratification to be valid, the principal must be aware of the material facts of the situation at the time they consent to the agent's actions. This means that the principal should have comprehensive information regarding the specific circumstances and consequences surrounding the agent's actions that they are seeking to ratify. Understanding these material facts allows the principal to make an informed decision about whether to accept or reject the actions taken by the agent on their behalf. Without this knowledge, the principal might unwittingly assume liabilities or obligations they did not intend to accept.

The other options, while potentially relevant in other contexts, do not specifically pertain to what the principal must know for valid ratification. For instance, knowing the financial status of the agent or the future actions they might take does not directly influence the legitimacy of the ratification process. Similarly, intentions of third parties may be important in different legal scenarios but are not a requirement for the principal's ratification of the agent's prior acts.