The correct option for punctuating the sentence appropriately is:
The professor demanded, “What makes you think that ‘discredited’ or ‘repudiated’ are synonymous with ‘defeated’ ?”
This choice is the most suitable because:
- The punctuation within the quotation marks is consistent; both instances of the term being compared and the term itself each have single quotation marks (‘’), which is necessary to indicate words being discussed rather than used in context.
- The question mark is placed correctly inside the final quotation mark, adhering to the rule that punctuation marks at the end of a sentence should be placed inside quotation marks if they are part of the quoted material.
- The initial capital letter in “What” indicates the beginning of the quoted question, maintaining correct sentence structure.