Final answer:
The correct title of the musical composition written by Sebastian for his star pupil cannot be determined without additional context from a specific text or curriculum.
Step-by-step explanation:
The title of the musical composition Sebastian wrote for his star pupil is not definitively provided in the question and can't be answered with certainty from the given options without additional context.
There is a possibility that the question refers to a fictional scenario or requires insight from a specific text or curriculum that isn't universally recognized.
Therefore, I cannot confidently provide the correct answer to which composition Sebastian wrote for his star pupil as the options given, such as Moonlight Sonata, Starry Night Symphony, Pupil's Serenade, and Nocturne in C Minor are standard titles that could relate to different composers or scenarios.
It is important to check the specific materials or references from the educational context for clarification.