Subtree merge allows integrating an external project into another by merging in only the parts needed, maintaining separate histories. It's useful for combining projects without losing their individual version control contexts.

The correct option is a) commit-hash. This command allows you to apply the changes introduced by a specific commit onto your current branch. You need to provide the commit hash of the desired commit.

Git's branching model enhances Agile methodologies by facilitating parallel development. Multiple branches enable teams to work on different features simultaneously, promoting collaboration and faster delivery. The ability to isolate features in branches helps manage project complexity and supports Agile principles of adaptability and quick response to changes.

Tags in Git are crucial for maintaining different versions of database scripts for various features. Tags provide a way to mark specific points in the version history, making it easier to reference and deploy specific releases of database scripts. This is especially useful when managing multiple versions of a database schema for different features or releases.

To navigate through each change individually and discuss them, you can use git log -p to show the commit history with the associated changes. git diff shows the changes in the working directory, but it's not specific to individual commits. git blame is used to show changes in a file, and git bisect is used for binary search to find a specific commit causing an issue.

The correct option is B. git bisect start is used to perform a binary search through the commit history, helping identify the commit that introduced a bug. The bisect command automates the process of checking out different commits until the problematic one is found.

The git clone command is used to clone a remote repository to your local machine. It copies the entire repository, including all branches and commit history, to your local system.

Code linting in Git can be automated in an IDE to ensure code quality before commits. Linting checks the code for potential errors, stylistic issues, and adherence to coding standards, helping developers catch and fix issues early in the development process.

'Feature branches' are long-lived branches created for ongoing features or tasks. They allow developers to work on features independently and then integrate them back into the main branch when ready. This promotes a clean and organized development process.

A lightweight tag in Git only contains a reference to a specific commit, while an annotated tag includes additional information such as a tagger name, email, date, and a tagging message. Annotated tags are recommended for important releases or milestones.