➜ demo git:(master) rm README.rdoc
➜ demo git:(master) ✗ g s
D README.rdoc
➜ demo git:(master) ✗ git rm $(git ls-files -d)
rm 'README.rdoc'
➜ demo git:(master) ✗ g s
D README.rdoc
➜ demo git:(master) rm README.rdoc
➜ demo git:(master) ✗ g s
D README.rdoc
➜ demo git:(master) ✗ g a -u
➜ demo git:(master) ✗ g s
D README.rdoc
NOTED BENEFIT OF OPTION A!
(doesn't included modified files)