Display Logic after DCE (Conjoint)

Dear all,
I have set up a Discrete Choice Experiment (DCE) using the conjoint tool from DesignXM. The choice tasks contain an opt-out option (selection of "none of the options" possible).
If respondents always choose the opt-out option I want to ask them after the DCE, why they always choose the opt-out option (general refusal/negative perception of the topic, or only too high/low price?).
However, I cannot add a display logic based on the responses of the choice tasks. The questions and answers are not accessible in later questions in the survey.
Does anybody have an idea, how to access the responses from the choice tasks to build a display logic based on the answers?
Thanks in advance!
Kati