Git is commonly used for version control in CI/CD pipelines. It provides a distributed version control system that allows developers to track changes in their codebase efficiently.

The CSS pseudo-elements allow you to style Structural parts of an element. They enable you to style specific parts of an element, such as the first line or first letter.

In a pull request, the Reviewer is responsible for reviewing and providing feedback on the proposed changes. This role ensures the quality and adherence to coding standards before merging.

"Granular recovery" in backup strategies refers to the ability to recover individual items or files rather than restoring the entire system. This approach provides flexibility and efficiency, allowing users to retrieve specific data without the need for a full system restoration.

Google Cloud Storage is the optimal choice for storing and analyzing large amounts of unstructured data. It provides low-latency access, strong consistency, and integrates seamlessly with Google Cloud's powerful analytics and machine learning tools.

The Decorator design pattern adds additional responsibilities to objects without altering their structure. This pattern is useful for extending the functionalities of objects dynamically.

The correct design pattern for ensuring a single instance of a class is the Singleton pattern. This pattern restricts the instantiation of a class to one object and provides a global point of access to that instance. It's commonly used for scenarios like managing database connections to maintain consistency across the application.

Techniques for optimizing frontend performance in SPAs include Code Splitting, which involves breaking the code into smaller chunks and loading only what is necessary for a particular view. This reduces initial loading times and improves the overall user experience.

Docker is primarily used for containerization. It allows developers to package applications and their dependencies into containers, ensuring consistency across different environments and simplifying deployment. Containerization, as facilitated by Docker, enhances scalability, portability, and resource efficiency.

Option c is the most appropriate. Documentation is crucial, especially for critical changes. Rejecting the pull request until documentation is provided ensures comprehensive understanding and accountability.