Others, specify option in multiple choice

Hie guys, suppose you have multiple choice questions with answers but the last option gives freedom for the respondents to specify what answer they have, How would you write this in xls?

You can have other option and add logic that if it's selected an extra (text for example) question will be displayed.
Something like in this sample: Specify Other when Other is selected with other choices in a select multiple form - #2 by Grzesiek2010