The question statement is incomplete: the reaction scheme is missing, and all options A–D are blank. Because the identity of final product $C$ depends entirely on the given sequence of reactions, it is not possible to derive the answer from the provided information.

What is missing

1. The actual series of reactions leading to product $C$.
2. The structures/options corresponding to A, B, C, and D.

Without these, no chemical analysis can be performed.

Conclusion

I cannot validly solve the problem as stated because the essential reaction data is absent. Please provide the reaction sequence image/text and the option structures.

Since the stored correct answer is given as C, but there is no usable question content to verify it, I cannot honestly confirm that choice from chemistry reasoning alone.