Hello 3vra
Which version of VirtualBox are you running? According to the 3.0.0 User manual "
To enable bridged networking, all you need to do is to open the Settings dialog of a virtual machine, go to the “Network” page and select “Bridged network” in the drop down list for the “Attached to” field." I'm running 3.0.2 and it does show the “Bridged network” option.
Again according to the 3.0.0 User manual "
The way bridged networking works has been completely rewritten with VirtualBox 2.0 and 2.1, depending on the host operating system. From the user perspective, the main difference is that complex configuration is no longer necessary on any of the supported host operating systems".
Best
Charles