To toggle live results display for a question, open the project admin page to the 'Page & Survey' tab:
Scroll to the question you'd like to enable/disable results display for and click the gear icon (View Results and Edit):
You can then toggle public results display on and off by clicking the "Show response counts and results to participants" switch:
Changes will save automatically. You can return to the public survey to preview the appearance of this question and its real-time display.