On the Results tab of a quiz, scroll down the page to the section called Engaging Networks integration:
Click the toggle to Enable Engaging Networks integration.
You will then need to do two things: choose the data capture page in your Engaging Networks account that quiz entries will be submitted to; and map the form fields you are using against your fields in Engaging Networks.
First of all, choose your data capture page from the dropdown:
Then map each of the quiz form fields against your fields in Engaging Networks: