Final answer:
The boy's name in the NATO phonetic alphabet that represents a vowel is 'Oscar', which stands for the vowel letter 'O'.
Step-by-step explanation:
The boy's name from the NATO phonetic alphabet that represents a vowel is Oscar, which phonetically denotes the letter 'O.' The NATO phonetic alphabet is used to spell out words in a universally recognized way, especially over radio and telephone where letter clarity is important.
The other options provided, such as Pip, Max, and Alpha, do not correspond to vowels; in fact, Alpha represents the letter 'A', which is indeed a vowel in the alphabet but not a boy's name. Therefore, the correct answer is C. Oscar.