TOPIC: analyze or ignor the situation with procurements

You have recently made the final delivery of your software project to the customer. Before making the release, you ensured that thorough testing was done and project scope was verified. After a week of taking delivery, the customer shows his dissatisfaction with the release and says the product doesn't support a critical functionality. He asks you to add this feature immediately. What should you do?

A: Understand the customer requirement and estimate the additional time and resource required to complete it, Communicate the same to the customer
B: Discuss the customer feedback with the senior management and seek their advice on the matter
C: Analyze the in-house process of testing and scope verification to determine the root cause of the problem
D: Ignore the customer and proceed with project closure activity

This is another question. I picked C which appears to be wrong. The author is saying D is correct.
Strangely I came across similar question few weeks back and picked D at point but C was the correct choice which sort of made sense to me.
However today I got conflicting opinion.
Any recommendations please?

Muhammad,

Who is the author of this question please?

Sorry again. I'll make sure future posts have the author.

This question is from simplilearn.com. I also mentioned reference to another question (sorry I forgot the source - will try to dig out)
The key bit is what is recommended in this situation.

Regards,
Saeed

Hello Muhammed,

Actually D is the first answer I would discard while trying to answer this question. Ignoring the customer is not an option, I think.
I would suggest that you double check the answer with the question author and ask for clarification.

D is the least likely answer and seems to be a typo. As Ahmed said, you can recheck it with them.