The correct answer is C. PaaS.
PaaS (Platform as a Service) is a type of cloud computing that provides a platform for developing, testing, and deploying applications. PaaS providers offer a set of tools and services that make it easier to develop and manage applications. This can include things like a programming language, a database, and a web server.
Appear IQ, Mendix, Amazon Web Services (AWS) Elastic Beanstalk, Google App Engine and Heroku are all examples of PaaS providers.
IaaS (Infrastructure as a Service) is a type of cloud computing that provides access to computing resources such as servers, storage, and networking. IaaS providers offer a way to rent these resources on an as-needed basis. This can be a more cost-effective way to get access to these resources than buying them outright.
SaaS (Software as a Service) is a type of cloud computing that provides access to software applications over the internet. SaaS providers offer a way to use these applications without having to install them on your own computer. This can be a more convenient and cost-effective way to use software applications.
D is not a correct answer because it is not one of the three main types of cloud computing.