The question asks: Which reaction is NOT possible?

However, the actual reaction options for A, B, C, and D are missing from the prompt. Since no chemical equations/structures are provided, it is not possible to independently evaluate which reaction cannot occur.

Step 1: What is needed

To solve this type of organic chemistry MCQ, I would need the actual reactions under options A, B, C, and D, for example:

• reactant(s)
• reagent(s)/conditions
• product(s)

Without those, no chemical reasoning can be applied.

Step 2: Limitation

Because the options are blank, I cannot derive the answer from chemistry principles alone.

Step 3: Comparison with stored answer

The stored correct answer is C. But since the reaction options are absent, I cannot verify whether C is truly correct.

Hence, I must mark that I do not have enough information to agree confidently with the stored answer.