Question

In which sentence is the underlined word an indefinite article?

Answer 1

There are only two indefinite articles known in English: "a" and "an". Therefore, the correct answer is c. I found a bag of marbles.

"The", however, is a definite article.

Hope this helps~

Answer 2

C. I found a bag of marbles.

This is the only sentence that contains an indefinite article. Indefinite articles are "a" and "an" for singular nouns. "some" is the indefinite article used for plural or uncountable nouns.

"the" is a definite article.