The correct answer is: A. EC2
Amazon Elastic Compute Cloud (EC2) is a web service that provides resizable compute capacity in the cloud. It is a virtual server platform that allows users to create and run virtual machines on Amazon’s server farm. EC2 provides a broad set of features, including high availability, scalability, security, and networking.
Azure is a cloud computing service created by Microsoft for building, testing, deploying, and managing applications and services through a global network of Microsoft-managed data centers. It provides software as a service (SaaS), platform as a service (PaaS), and infrastructure as a service (IaaS) and supports many different programming languages, tools, and frameworks, including both Microsoft-specific and third-party software and systems.
EC5 is a discontinued virtual server platform that was offered by Amazon Web Services. It was a high-end offering that was designed for demanding workloads. EC5 was discontinued in 2017 and replaced by EC2 instances with more powerful processors.
None of the mentioned is not a correct answer.