A.I. Explanation:

Correct answer: remains

Explanation: The word 'remains' fits grammatically as it indicates a state of being, suggesting that Plato continues to hold his status as one of the greatest philosophers. It aligns with the present tense context of the sentence, indicating ongoing relevance.

Meaning: 'Remains' means to continue to exist or stay in a particular state, emphasizing Plato's lasting influence in philosophy.

Wrong options:

• keeps: 'Keeps' implies maintaining possession or control, which does not fit the context of philosophical status.
• comes: 'Comes' suggests arrival or emergence, which is not appropriate for describing a philosopher's enduring status.
• claims: 'Claims' indicates assertion or declaration, which does not accurately convey the idea of ongoing status.

Correct answer: However

Explanation: 'However' serves as a discourse marker that introduces a contrast to the previous statement about Plato's influence, fitting well grammatically and contextually to indicate a shift in focus to the challenges faced by his theories.

Meaning: 'However' means 'nevertheless' or 'on the other hand,' signaling a contrast to the previous idea about Plato's influence.

Wrong options:

• Notwithstanding: 'Notwithstanding' is more formal and does not fit the conversational tone of the sentence as effectively as 'However.'
• So: 'So' implies a consequence rather than a contrast, which does not align with the intended meaning of the sentence.
• Whatever: 'Whatever' suggests indifference and does not provide the necessary contrast to the previous statement.

Correct answer: whether

Explanation: The word 'whether' introduces a clause that presents an alternative or condition, fitting grammatically as it questions the existence of the ideal society in reality. It aligns with the context of doubt or inquiry regarding Plato's theories.

Meaning: 'Whether' is used to introduce alternatives or possibilities, indicating uncertainty about the existence of the ideal society.

Wrong options:

• which: 'Which' is used for specifying or identifying, but does not convey the sense of doubt or choice present in the context.
• that: 'That' is used to introduce defining clauses, which does not fit the interrogative nature of the sentence.
• what: 'What' is used for inquiries about specific things, but does not appropriately introduce the conditional aspect of the question.