You need to configure a distribution group named CustomerService that has the following configurations:
A user named CSManager must be the only user allowed to add members to CustomerService.
All email messages sent to CustomerService must be approved by CSManager.
External users must be allowed to send email messages to CustomerService.
You configure CSManager as the group owner.
What should you configure in the Exchange admin center for each requirement?
To answer, drag the appropriate configurations to the correct requirements. Each configuration may be used
once, more than once, or not at all. You may need to drag the split bar, between panes or scroll to view content.
Select and Place:
Answer: 
1 – Membership Approval
2 – Moderation
3 – Delivery Management
I would agree with Larry
If there were some options to chose from in the first place! But option 1 would be a bit different. The membership approval is a bit different. The owner of the group with it’s options would exclusively allow only him to add new members.
1) Already configured (Ownership) so the required option would be: MyDistributionGroups – which will allow him to edit membership
2) Moderation sounds correct – the CSManager will approve/reject the messages to the group
3) Delivery Management – option from the group properties to allow messages from inside and outside the organization