Correct Answer:
A. achieve
The sentence "Despite working hard, he could not __________ success" implies a contrast: even with significant effort, a desired positive outcome (success) was not attained. We need a verb that conveys the idea of reaching or gaining success.
- A: achieve means to successfully bring about or reach (a desired objective or result) by effort, skill, or courage. This fits the context perfectly, indicating that despite his hard work, success remained out of his grasp.
- B: failed is a verb meaning to not succeed. If used, the sentence structure would be different, such as "he failed to achieve success" or "he failed to succeed." It doesn't fit directly after "could not."
- C: lose means to be deprived of or cease to have or retain (something). This is contrary to the idea of gaining success.
- D: avoid means to keep away from or stop oneself from doing (something). This is the opposite of what someone working hard for success would do.
Therefore, "achieve" is the only word that logically completes the sentence, conveying the intended meaning of not attaining success despite diligent effort.