The correct answer is “a”.
The word “handsome” is an adjective that describes a person’s appearance. It is typically used to describe a man who is attractive or pleasing to look at. In this case, the speaker is describing a boy who is handsome.
The article “a” is used before singular nouns that refer to a general class of things. In this case, the speaker is not referring to a specific boy, but rather to boys in general.
The article “an” is used before singular nouns that begin with a vowel sound. In this case, the word “handsome” does not begin with a vowel sound, so the article “a” is used.
The article “the” is used before singular nouns that refer to a specific person or thing. In this case, the speaker is not referring to a specific boy, so the article “the” is not used.
The answer “none of the above” is incorrect because the speaker is using the article “a”.