The correct answer is 'Indefinite article'. Key Points - Here, in the given above sentence the underlined part "a" is used as an indefinite article. - As per the general rule, A determiner a and an in English introduces a noun phrase and implies that the thing referred to is nonspecific Typically, the indefinite article is used to introduce new concepts into a discourse. - a- "indefinite article 'a' is used before a singular noun beginning with a consonant sound". - an- "indefinite article 'an' is used before a singular noun beginning with a vowel sound. - Example: - The sushi chef-prepared meals for a hungry crowd. - It was an early morning for me. - Here, in the given above examples, 'a and an' can be used as an indefinite article. - According to the explanation and example that are given above, 'Indefinite article' is the correct part of speech for the given above sentence.