Correct option is C
Option (c) is the correct order of the given sentences.
The correct order is: The school Cultural Society organised a musical night last week (D). The event was held to raise funds for the slum adopted by the school (A). The contributions from the parents and teachers were amazing (C). The Principal thanked everyone for the contributions which would help in the development activities (B).
D introduces the event, A provides the reason, C describes the outcome, and B concludes with thanks.