Which of the following statements is true when using Block Components in OutSystems?

Using Block Components in OutSystems allows developers to encapsulate reusable functionalities, making option C the correct choice. Block Components serve as modular pieces of code that can be defined once and reused throughout an application. This promotes better organization, maintainability, and reusability within the development process.

When a Block Component is created, developers can define inputs and outputs, allowing these components to interact flexibly with the rest of the application. This encapsulation is crucial in software development as it adheres to the principles of DRY (Don't Repeat Yourself), enabling developers to avoid duplication of code and simplify their overall application architecture.

The other options suggest limitations that are not applicable. For instance, Block Components can accept parameters, enhancing their reusability across different contexts. They are not fixed and have the flexibility to be designed according to the needs of the application. Event handling is also supported, allowing for interactions and dynamic behaviors within the components, which further extends their capabilities beyond what is suggested in other choices. The encouraging flexibility and functionality of Block Components contribute significantly to efficient and effective application development in OutSystems.