The correct answer is: B. git add -u
The git add command adds files to the staging area, which is a temporary place where files are stored before they are committed to the repository. The -u option tells git to add only files that have been modified since the last commit.
The git add . command adds all files in the current directory to the staging area. This can be useful if you want to commit all changes to the current directory. However, it can also be dangerous if you have accidentally modified a file that you don’t want to commit.
The git add -A command adds all files in the current directory and its subdirectories to the staging area. This can be useful if you want to commit all changes to the current directory and its subdirectories. However, it can also be dangerous if you have accidentally modified a file that you don’t want to commit.
In conclusion, the git add -u command is the safest way to add files to the staging area because it only adds files that have been modified since the last commit.