A) Application-specific data assets are the responsibility of the organization in a PaaS implementation. The organization owns and controls its own data and must ensure its confidentiality, integrity, and availability. The organization must also comply with any applicable data protection laws and regulations.
B) Application user access management is the responsibility of the organization in a PaaS implementation. The organization must define and enforce its own policies and procedures for granting, revoking, and monitoring access to its applications and data. The organization must also ensure that its users follow security best practices such as strong passwords and multifactor authentication.
C) Application-specific logic and code are the responsibility of the organization in a PaaS implementation. The organization must develop, test, deploy, and manage its own applications using the tools and services provided by the platform. The organization must also ensure that its applications are secure, reliable, and performant.
https://www.techtarget.com/searchcloudcomputing/feature/The-cloud-shared-responsibility-model-for-IaaS-PaaS-and-SaaS Explanation:
In a PaaS implementation, the provider offers relief to the organization's teams by sharing in many of the operational duties related to the application/platform software. The provider is responsible for securing and maintaining the underlying infrastructure, operating systems, middleware, runtime environments, and other software components that support the platform and the applications running on it. The provider also handles tasks such as patching, updating, scaling, and backing up the platform software.