23 The service at that restaurant is second .....

Analysis:

The sentence describes the restaurant's service. The idiom 'second to none' means the best.

Breakdown:

• A standard: Incorrect. 'Second standard' is not an idiom.
• B rate: Incorrect. 'Second rate' means of inferior quality.
• C grade: Correct. 'Second to none' is the idiom meaning the best.

Translated Question:

23 Обслуживание в том ресторане — второе .....