Ambiguity is often preferred by people.

Answer: Option A

Ambiguity : the quality of being open to more than one interpretation; inexactness.
Clarity : the quality of being coherent and intelligible.
Perversity : a deliberate desire to behave in an unreasonable or unacceptable way; contrariness.
Rationality : the quality of being based on or in accordance with reason or logic.
Certainty : firm conviction that something is the case.

Antonym of Ambiguity is Clarity