You are a global administrator of a company with an Azure tenant. You have currently no Azure subscription enabled. You want to turn on Customer LockBox for your organization and must choose an Azure subscription that supports the solution. What is the most cost-effective Azure subscription plan that supports Customer LockBox?

Answer options:

A.Basic
B.Developer
C.Standard
D.Professional Direct

Correct Answer: B 
Customer LockBox required an Azure support plan with a minimal level of Developer.
Option A is incorrect. This plan does not support Customer LockBox
Option C is incorrect. This plan does support Customer LockBox, but the Developer-plan is more cost effective.
Option D is incorrect. This plan does support Customer LockBox, but the Developer-plan is more cost effective.
Reference: 
To know more about Customer Lockbox, please refer to the link below: 

https://docs.microsoft.com/en-us/azure/security/fundamentals/customer-lockbox-overview