Final answer:
The nearest antonym of 'vanquished' is 'triumphed,' as it represents the opposite meaning, which is to win or be victorious.
Step-by-step explanation:
The word vanquished means to be completely defeated or overcome in battle or in a contest. To find the antonym of vanquished, one must look for a word that means the opposite, which is to win or prevail. Thus, the closest antonym to vanquished from the options provided is triumphed (E), as it means to win or be victorious. The other options do not accurately represent the opposite of vanquished. Therefore, the nearest antonym of vanquished in the given context is triumphed.