The correct answer is C. Disruptive
Explanation:
The word "disruptive" is an adjective that describes people, elements or situations that stop or interrupt one activity. In the case of cell phones, the use of this during the classroom is disruptive because it interrupts the normal development of the class by distracting students or causing students are not focused on the activities of the class. Thus, the best word to complete this sentence is disruptive because the loud noises of the sound disrupt or interrupt activities or processes in the class.
