The model of practice guiding the OTR®'s intervention in this scenario is
B. Acquisitional.
In occupational therapy, the acquisitional model emphasizes the importance of providing diverse experiences, various media, and novel instructional materials to promote skill acquisition and learning. This approach is often used in handwriting interventions to help individuals develop and refine their handwriting skills through different activities and materials, enhancing their ability to acquire and master these skills.