The correct option is C the wisest
The sentence is of the superlative degree when the noun is of the highest degree in terms of quality. In the sentence, the noun 'man' is the 'wisest', where 'wisest' is of the highest degree or the superlative of 'wise'. Hence option D is correct. Option A is incorrect as the article 'the' is necessary to modify the noun, because the superlative 'wisest' makes the noun specific, as there can only be one highest degree. 'Most' precedes an adjective when the adjective has more than two syllables, 'wise' has only one syllable, hence 'most' is not used here, and options B and C are incorrect.