18. My employer didn't believe my claim until my colleagues……….. my story.

Answer: A

Explanation:

My colleagues corroborated my story.

The claim was validated when my colleagues corroborated my story, meaning they provided support or evidence that confirmed my account.

A) corroborated

This option is correct because "corroborated" means to confirm or give support to a statement or theory, which directly aligns with the context of the employer needing validation of the claim through my colleagues' support.

B) contradicted

This option is incorrect as "contradicted" means to assert the opposite of a statement, which would undermine my story rather than support it. If my colleagues had contradicted my story, it would have likely led to my employer doubting my claim even more.

C) counteracted

This option is also incorrect. "Counteracted" refers to acting against something to reduce its force or neutralize it. If my colleagues had counteracted my story, it would imply they worked against my claim, further diminishing its credibility.

D) augmented

This option is incorrect as well. "Augmented" means to increase or enhance something, but it does not imply the validation or support necessary for my story. Merely augmenting my story does not confirm its truthfulness in the context needed for my employer to believe my claim.

Conclusion

In summary, the correct answer is "corroborated" because it signifies that my colleagues provided essential support to my claim, thereby convincing my employer of its validity. All other options either negate my story or fail to provide the necessary confirmation that was required in this scenario.