Correct Answer: (b) an young businessman
Note: We use the article 'a' before the words starting with a Consonant(B,D,F,N,etc.) for example, a dirty shirt, a neglected department, etc. However, the article 'an' is used before words starting with a vowel (A,E,I,O,U) for example, an educated person, an imminent danger, etc. Hence, 'a young (Consonant 'y') businessman' is the most appropriate structure.