What should the project manager do first?

During the execution of a construction project, one of the neighboring businesses is complaining that the current building height does not agree with the initial project plans.

What should the project manager do first?
A . Ask the neighbor to leave the site immediately because the site is on private property.
B. Inform the neighbor that all of the project documentation has been approved.
C. Inform the neighbor that the complaint will be escalated to the project sponsor.
D. Ask the neighbor to submit a formal complaint about their concerns.

Answer: D