The correct answer to this question is A) An historian may keep asking more questions, keep searching other sources, and keep writing.
A historian can acknowledge personal bias yet stay true to the historic method by asking more questions, keep searching other sources, and keep writing.
The historian knows that he has to maintain its objectivity all the time when doing research. If by any motive it shows bias, it is b¿very important that can differentiate its bias and opinion with facts. It has to be very clear for the reader to know the difference from facts, hard data, from the bias of the author. This way, the historian can add up to its work with more sources, facts, statistics, secondary resources and keep on writing its conclusions.