Correct Answer: Inferior

Solution : The correct choice is the third option.

Explanation: In this context, when describing something as "superb", it means it is of exceptional quality. The opposite of exceptional quality would be something of lesser quality or rank, which is captured by the word "inferior".

The meanings of the other options are as follows:

• Infallible means incapable of making mistakes or being wrong.
• Incorrigible means incapable of being corrected, reformed, or improved.
• Splendid means magnificent or excellent in appearance.

Therefore, the correct answer is inferior.