Security guidance - Page 91 : " Virtualization isn't merely a tool for creating virtual machines-it's the core technology for enabling cloud computing. We use virtualization all throughout computing, from full operating virtual machines to virtual execution environments."
Security guidance - Page 92 : "As mentioned in the introduction, cloud computing is fundamentally based on virtualization: It's how we abstract resources to create pools. Without virtualization, there is no cloud."
Therefore, Cloud infrastructure security includes virtualization components.
The original question (in the screenshot) is a good question. It tests both your knowledge and your focus. You may need to read the question more than once to make sure you're not missing or overlooking anything in the text. Obviously if you have a strong knowledge and understanding of the topic, you won't get confused by that type of question. And as rightly said in previous replies, you can always use logic and check the guidance document, if in doubt.