A nurse is reinforcing teaching with the parents of a child who has ADHD and is taking methylphenidate. Which of the following statements by the parents indicates that the medication is effective?

ADHD (Attention-Deficit/Hyperactivity Disorder) is characterized by symptoms such as difficulty sustaining attention, impulsivity, and hyperactivity. Methylphenidate is a commonly prescribed medication for ADHD that helps improve focus, attention, and impulse control. The ability to complete homework on time suggests improved focus and attention, which are positive effects of methylphenidate in managing ADHD symptoms. It indicates that the medication is helping the child stay on task and concentrate better, leading to improved academic performance. "Our child has lost some weight since his last appointment" suggests a potential side effect of methylphenidate, which can cause appetite suppression and weight loss. "Our child has increased his daily caloric intake" might be a response to the weight loss side effect, but it does not directly indicate the effectiveness of the medication. "Our child has a better grasp of reality" is a subjective statement that does not specifically relate to ADHD symptoms or the expected effects of methylphenidate.