Answer: Withholding information
Explanation: Withholding information refers to not stating a fact that can influence the decision of the other party, even knowing it properly. In some cases it is considered as a crime in the eyes of law.
In the given case, the agent and the seller are obligated to disclose any existing problem even though the buyer did not know about it or get any idea of it.
Hence from the above we can conclude that the correct option is B.
