How does the word "feeble" affect the meaning of the sentence?

A. Feeble contrasts with vigorous to emphasize the difference between 'I think' and 'I know.'
B. Feeble explains old times to show that only older pilots were weak.
C. Feeble follows from ventured to draw attention to how strong pilots did their job.
D. Feeble supports scorn to show that pilots were taken seriously.

The word 'feeble' is used to contrast with 'vigorous' to emphasize the weakness of an assertion compared to a strong claim. It does not necessarily imply older pilots were weak or suggest that pilots' strength is being emphasized. The incorrect options suggest meanings that are not supported by the use of 'feeble.'

Explanation:

The word feeble in a sentence can significantly alter the meaning, with its influence depending on the context. In option a, feeble is used to create a contrast, highlighting the difference between a weak assertion ('I think') and a strong one ('I know'). Option b is incorrect since feeble does not imply that only older pilots were weak. Option c does not correctly interpret the word since feeble being used after 'ventured' would not necessarily draw attention to the strength of pilots.

Lastly, option d is incorrect as feeble does not support the notion that pilots were taken seriously; if anything, it would suggest the opposite, indicating that they were not taken seriously because they were perceived as weak or ineffective.