The correct option is A Singularity
Antonyms are words which have the opposite meaning in comparison to the other. Option A)singularity is correct as the word singularity means the state, fact, quality, or condition of being singularand the word medley means a varied mixture of people or things. The other options are wrong as sporadic, extrinsic, and robust mean occurring at irregular intervals or only in a few places; scattered or isolated, not part of the essential nature of someone or something; coming or operating from outside, and strong and healthy; vigorousrespectively. The correct answer is A)singularity.