Choose the correct option to fill in the blank in the given sentence:-

The students listened _____ to the teacher's instructions, ensuring that they understood every detail.

attentively

The correct answer is Option (3) → attentively

Correct sentence: The students listened attentively to the teacher's instructions, ensuring that they understood every detail.

Explanation: The word "attentively" means with careful attention or concentration, which fits the context of students making sure they understand every detail.