A public Cloud Service Provider (CSP) has sold Platform as a Service (PaaS) services to a real estate company. They worked with Daniel, the lead cloud architect, to design how their data would flow across the systems and enable the users to do their jobs. The CSP then worked with a manufacturing company to build a virtual Data Center (vDC). They worked with Shana at the manufacturing company to ensure that they had everything they needed to build their Infrastructure as a Service (IaaS) environment. What characteristic of the public cloud is the CSP responsible for securing for these companies?