The correct answer is: C. PaaS
PaaS (Platform as a Service) is a cloud computing model that provides a platform for developing, testing, and deploying applications. It is the highest degree of integration in cloud computing because it provides the most abstraction from the underlying infrastructure.
SaaS (Software as a Service) is a cloud computing model that provides software applications over the Internet. It is a lower degree of integration than PaaS because it does not provide the same level of control over the underlying infrastructure.
IaaS (Infrastructure as a Service) is a cloud computing model that provides access to computing resources, such as servers, storage, and networking, over the Internet. It is the lowest degree of integration than PaaS and SaaS because it provides the least amount of abstraction from the underlying infrastructure.
In conclusion, PaaS is the highest degree of integration in cloud computing because it provides the most abstraction from the underlying infrastructure.