Answer:
(D.) Foolproof and Unreliable
Step-by-step explanation:
A. Controversy and Similarity:
Controversy: It means usually means prolonged disagreement.
Similarity: It means when something is comparable.
They are neither synonyms nor are they antonyms, they mean nothing alike.
B. Plagiarism and Forgery
Plagiarism: When someone copies something word for word.
Forgery: When you copy something, essentially.
They are synonyms.
C. Subjective and Substantial
Subjective: Essentially means opinionated.
Substantial: Of considerable size/worth.
Not synonyms or antonyms.
D. Foolproof and Unreliable
Foolproof: Reliable, easy to do.
Unreliable: Prone to messing things up.
They are opposites, and therefore, antonyms.