Final answer:
To complete the sentence 'Las chicas son de México. Ellas son mexicanas.' the correct word to use is 'mexicanas' which agrees with the feminine plural subject 'chicas'.
Explanation:
Las chicas son de México. Ellas son mexicanas.
In this sentence, the word that best completes it is 'mexicanas', which agrees with the feminine plural subject 'chicas'.
Adjectives in Spanish must match the gender and number of the nouns they describe, so 'mexicanas' is the correct form here.
Learn more about Spanish adjectives here:
https://brainly.com/question/30766245
