Question

doubt has the same or almost the same meaning as
idealism
question
humanity
rationalism

Explanation:

"Doubt" implies a state of being uncertain or having questions. "Question" can also refer to a query or a state of uncertainty in a similar sense. "Idealism" is about abstract ideals, "humanity" refers to human - kind or human qualities, and "rationalism" is about relying on reason.

Answer:

B. question