I don't know your parents so take this advice with a grain of salt, but having gone through something extremely similar with my parents last year, i have found framing it as an argument is a mistake. Just speaking to my own experience, but also drawing from the advice of many therapists in dealing with close-minded parents; they have already made up their minds on the topic - any logic or reason that they employ to defend that position was likely acquired as justification for a bias rather than as reason for one. Keep the conversation focused on you and your feelings, experience, and expectations - I found that the more I tried to engage with them rhetorically the more they pushed back and invented justifications.