The question refers to a multistep reaction, but the actual reaction scheme and most of the option structures are missing in the provided prompt. Only option C is visible as:

$\mathrm{CH_3-CH_2-CH_2-CH_2-OH}$

while options A, B, D are blank, and no reaction sequence is shown.

Step 1: What is needed to solve this question?

To determine the product of a multistep organic reaction, we must know:

1. The starting compound
2. The reagents/conditions in each step
3. The structures of all options

Without these, the product cannot be derived.

Step 2: Can we infer the answer from the visible information?

No reliable inference can be made, because:

• The reaction pathway is absent.
• Option D is not shown.
• The stored correct answer says D, but we cannot verify what compound D actually is.

Step 3: Comparison with stored correct answer

Since the reaction scheme is missing, I cannot independently derive the product. Therefore, I cannot honestly confirm that D is correct from chemical reasoning.

So, based on the incomplete data:

• I do not agree that the answer can be validated as D.
• A proper solution requires the full reaction image/scheme and all option structures.