The correct answer is D. impartial.
An impartial person is someone who does not favor one side over another. They are fair and objective in their judgment.
An unbiased person is someone who does not have any preconceived opinions or beliefs about a particular subject. They are open to all sides of an issue and are not influenced by their own personal feelings or experiences.
A prejudiced person is someone who has a negative opinion about a particular group of people based on their race, religion, or other characteristics. They are often intolerant and discriminatory.
A neutral person is someone who does not take sides in a conflict or disagreement. They are objective and fair in their judgment.
In the given question, the person is described as never taking sides but always remaining impartial. This means that they are fair and objective in their judgment, and they do not favor one side over another.