The words 'intelligent' and 'smart' are both adjectives that modify the noun 'reporting manager'. Articles modify nouns, or when an adjective precedes a noun, then the article modifies the adjective. If an adjective is not followed by a noun then we don't use any article. Hence option D is correct. As the adjectives do not precede any nouns in this sentence, option D) no article would be correct and options A, B and C are incorrect.