How to change Screen Resolution for Virtual Box running Mac Virtual Machine

1. Click on Finder --> Preferences --> Sidebar
   then check Hard disks

2. Open the Hard disk and navigate to Extra folder.
Add the following lines to org.chameleon.Boot.plist file and save it

<key>Graphics Mode</key>
<string>1600x900x32</string>

3. Shutdown the OS, then the machine

4. Close Virtual Box

5. Start the command line and navigate to where you installed virtual box.

cd C:\Program Files\Oracle\VirtualBox

6. Execute the following command:

VBoxManage setextradata "Mac OS Mavericks" "CustomVideoMode1" "1600x900x32"

7. Start the Virtual Box and then Start the Virtual Machine