A company is currently planning to set up resources as part of its Azure subscription. They are looking at different security options that can be used to secure their Azure environment. 
Which of the following could be used for the following requirement? 
“Provide an extra level of security when users log into the Azure Portal.”

Answer options:

A.Azure Key Vault
B.Azure Network Security Groups
C.Azure Multi-Factor Authentication
D.Azure DDoS Protection

Answer – C 
The extra level of security can be accomplished by providing a facility of Multi-Factor Authentication. 
The Microsoft documentation mentions the following. 

Option A is incorrect since this is used to store secrets, certificates and keys. 
Option B is incorrect since this is used to restrict traffic into and out of Azure virtual machines. 
Option D is incorrect since this is used to protect against Distributed denial of service (DDoS) attacks. 
For more information on multi-factor authentication, please visit the below URL- 

https://docs.microsoft.com/en-us/azure/active-directory/authentication/concept-mfa-howitworks