You need to grant rights to the developers without assigning unnecessary privileges

You are administering SQL Server Integration Services (SSIS) permissions on a production server that
runs SQL Server 2012.
Package developers in your company must have permission to perform the following tasks only on their
own projects:
View projects and packages, View Environments, Validate packages, Execute packages.
You need to grant rights to the developers without assigning unnecessary privileges.
What should you do? (Each correct answer presents part of a solution. Choose all that apply.)

A.
Add developer logins to the db_ssisltduser role in the msdb database.

B.
Add developer logins to the db_ssisoperator role in the msdb database.

C.
Grant Execute permission in the projects for the developer logins.

D.
Grant Read permission in the SSIS catalog folder, the projects, and the Environments.

E.
Add developer logins to the ssis_admin role in the SSISDB database.

F.
Grant Modify permission in the projects for the developer logins.

Explanation:
B: db_ssisoperator
* Read actions
Enumerate all packages.
View all packages.
Execute all packages.
Export all packages.
Execute all packages in SQL Server Agent.
* Write actions
None
D: Need read permissions on the Environments in order to be able to view them.
Incorrect:
Not A: db_ssisltduser
* Read actions
Enumerate own packages.
Enumerate all packages.
View own packages.
Execute own packages.
Export own packages.
* Write Actions
Import packages.
Delete own packages.
Change own package roles.
Not E: db_ssisadmin
Too many permissions (such as delete all packages).