SCOPE question

The scope of your project is very well defined and you have completed all the work described in the contract to your satisfaction, but you think your buyer is not happy with the work. What should you do? 
 
 
  Choice 1 Go through arbitration proceedings to ensure that disputes are resolved
 
  Choice 2 Talk with senior management about changing the scope of the project to accommodate requirements that would satisfy the customer
 
  Choice 3 Ask customer for inputs and get her advice on changes that need to be made
 
  Choice 4 Move to contract close-out

 option 4??