Can someone please respond how b) is correct answer

Which one of the following is the last step of project closing?

a)Archive Project Documents
b)Measure customer satisfaction at the end of the project
c)Client appreciates your product
d)Lessons learnt are documented
Explanations:

Answer (b) All of the stated options are activities conducted during project closing. Measure customer satisfaction at the end of the project is the last step in the closing process group. This is as per the new changes suggested by the PMI RDS Study.

I would chose A

The last step means y cant do any next step.

What to do after A?
But after D u still need to archive