With your cursor on "Ubuntu, with Linux 3.16.0-18-generic (recovery mode)", press 'e' and you should see 'recovery' specified somewhere on the line that starts 'linux'. If not, your grub config is incorrect for some reason.
To test if recovery mode works, again having pressed 'e', remove 'single' and replace it with 'recovery' then CTRL+x or F10 to boot into recovery mode.
With your cursor on "Ubuntu, with Linux 3.16.0-18-generic (recovery mode)", press 'e' and you should see 'recovery' specified somewhere on the line that starts 'linux'. If not, your grub config is incorrect for some reason.
To test if recovery mode works, again having pressed 'e', remove 'single' and replace it with 'recovery' then CTRL+x or F10 to boot into recovery mode.