A company is planning to use an entire suite of Microsoft products. Which of the following belongs to the category of Software as a service (SaaS)?

Answer options:

A.Azure Virtual Machine service
B.Microsoft Office 365
C.Azure App Service
D.Azure Content Delivery Network Service

Answer – B 
The Microsoft documentation mentions the definition of Software as a service (SaaS) below. 

Option A is incorrect since this belongs to the category of Infrastructure as a service (IaaS). 
Options C and D are incorrect since this belongs to the category of Platform as a service (PaaS). 
For more information on Software as a service, please visit the below URL- 

https://azure.microsoft.com/en-us/overview/what-is-saas/