Email Task - survey response triggering event.

From the Qualtrics website on triggering an email task, it says the task (in this case sending an email to the respondent with a link to a pdf) can be triggered after answering a question (partial completion of the survey) if the response to the question is recorded. Specifically, I have a question at the beginning of my survey that if selected should send an email with a link to a pdf of the survey. I would like that email to be sent after the answer to the question is recorded as opposed to the respondent having to complete the survey, which would require the respondent requesting a new link to the survey and me sending a email with a link for the participant to retake the survey. My testing of this email task requires that I complete the survey in order for an email to be sent. Any thoughts on how I can get the email task to trigger when the respondent selects the question and the answer to the question is recorded (in this case its the first question in the survey). The question is multiple choice with only 1 answer category (radio button).