In boys, what hormone stimulates the growth of the larynx and thickening and lengthening of the vocal folds, which causes the voice to drop in pitch during puberty?

The four Science Regents exams (Earth Science, Living Environment, Chemistry, and Physics) also include separately-scheduled lab practicals.
In New York, students have the opportunity to take Regents Exams in grades 9-12 and, when appropriate, in grade eight.