To create a symlink for /usr/local/bin/app-a, which was installed in /usr/local/share/app-a, the administrator can use the command ln -s /usr/local/share/app-a /usr/local/bin/app-a (A). This will create a symbolic link named /usr/local/bin/app-a that points to the original file /usr/local/share/app-a. The other commands will not create a symlink, but either move, copy, or synchronize the file. Reference:
[CompTIA Linux+ Study Guide], Chapter 3: Working with Files, Section: Creating Links
[How to Create Symbolic Links in Linux]