Could the company increase the SLA for their resources by purchasing (AZ-900)

Correct answer: B) No.
Purchasing multiple subscriptions alone does not inherently increase the SLA for Azure resources. The SLA for each individual Azure service is determined by Microsoft and is not directly tied to the number of subscriptions a company purchases. However, companies can architect their solutions to increase availability and reliability by distributing resources across multiple regions, utilizing redundancy and failover mechanisms, and implementing other high availability strategies. These actions can help achieve higher SLAs, but simply purchasing multiple subscriptions without such architectural considerations will not directly impact SLAs.