Select the most appropriate option to fill in the blank and make a grammatically correct sentence.

Jamuna found an old necklace and ______ gold bangles in the cupboard.

a pair of

The correct option to fill in the blank is a pair of.

The word "bangles" is a plural noun, so it needs a plural verb. The word "pair" is also a plural noun, but it is used to refer to two things that are the same. In this sentence, we are talking about two gold bangles, so we need to use the plural form of "pair."

The other options are not grammatically correct.

• An pair of is not a grammatically correct phrase. The word "an" is used before singular nouns that start with a vowel sound, but the word "pair" does not start with a vowel sound.
• Pair of is a correct phrase, but it is not the most grammatically correct option in this case. The sentence is about two gold bangles, so we need to use the plural form of "pair."
• A pairs of is not a grammatically correct phrase. The word "pairs" is plural, but the word "a" is singular. We cannot use a singular noun with a plural verb.