arrays - iterating over things in php

I have an array called $options.
I want iterate through it's contents, so I do:

 foreach($options as $option){   
    print_r( $option);
 }

The resulting output gives me an object/array heffalump that starts like this...

Mage_Bundle_Model_Option Object
(
    [_defaultSelection:protected] => 
    [_eventPrefix:protected] => core_abstract
    [_eventObject:protected] => object
    [_resourceName:protected] => bundle/option
    [_isObjectNew:protected] => 

    [_data:protected] => Array
        (
            [option_id] => 20
            [parent_id] => 291

I want to reference values in _data, but I am stumped as to correct syntax to do this...