As a project manager you need to decide for one of the following inputs to control scope. Which would you choose?

option2.

according to PMBOK project management plan is one of the inputs for control scope and scope management plan is one of its documents.

What to Include in a Project Scope Statement - For Dummies

www.dummies.com/.../what-to-include-in-a-project-scope-statement.html The Scope Statement is an essential element of any project. Project managers use the Scope Statement as a written confirmation of the results your project will ...

Therefore option 4

Scope Management Plan Template

The answer is Project Management Plan which include the following:

1. PM Activity Plan

2. PM Budget Plan

3. PM Resource Plan

4. PM Risk Plan

5. PM Scope Plan

6. Quality Plan

7. Changes

See my document on my starting new project template:

               http://sameldin.com/HTML_Code/NewProject.html

Option4

Ade Chandra simplified it well

Option4, because every things we do, we must start it from little things. Project scope statement is a part of scope management plan  if succeeding to overcome this we can handle scope management plan and the finally we can get project charter.

2 -Scope Management Plan is the input to Scope Control. Scope management plan ensures the scope creep is identified and documented at the right time.

project scope statement of work witch is include (WBS)

1. Scope management plan.....IF U WANT SOME THING GOOD U HAVE TO MAKE PLAN ABOUT THIS THING...

4th option, Project Scope Statement

I would go for Project Scope Statement since this is what sets the benchmark for the successful implementation of any Project

Option4 is the best choice.