Final answer:
The correct possessive adjective to complete the sentence is 'tes'. It means 'Your' in English, indicating possession by a singular noun belonging to someone informal (you).
Step-by-step explanation:
The correct possessive adjective to complete the sentence is tes. The sentence becomes Tes crayons sont dans le sac, which means 'Your crayons are in the bag' in English. In this case, 'tes' is used to indicate possession by a singular noun (crayons) belonging to someone informal (you).
Learn more about Possessive adjectives in French