Final answer:
The parent's statement indicating that the brace should be worn 23 hours a day reflects successful teaching about a brace for scoliosis correction in an adolescent.
Step-by-step explanation:
When assessing the effectiveness of teaching about a brace for scoliosis correction, the statement by the parent that indicates successful teaching is "The brace should be worn 23 hours a day." This is because scoliosis, which is an abnormal lateral curvature of the spine often worsening during an adolescent growth spurt, may require the constant support of a brace to correct the deformity. The brace acts to reinforce and support the spinal structure. It is important to note that options such as a bed board replacing the brace at night, a low-calorie diet, or a preference for tub baths are not directly related to the effectiveness of the brace in treating scoliosis.