Charlie has been diagnosed with attention-deficit/hyperactivity disorder (ADHD) .His medication improves his level of attention and helps him control his impulsive behavior, but he often experiences dryness in his mouth, fatigue, dizziness, and constipation.Which of the following drugs is Charlie most likely taking for his condition?

A) Ritalin
B) Dexedrine
C) Adderall
D) Clonidine

Clonidine is often used to treat ADHD, especially in individuals who may not respond well to stimulant medications. It can improve attention and impulse control but is known to cause side effects such as dry mouth, fatigue, dizziness, and constipation. Ritalin, Dexedrine, and Adderall are stimulant medications that primarily increase alertness and focus in individuals with ADHD, and while they can have side effects, the specific combination of side effects mentioned (dry mouth, fatigue, dizziness, and constipation) is more characteristic of Clonidine, which is a non-stimulant medication.