depends on the poll or survey
an official opinion poll, i’d tell truth
canvasser asking if they can count on my support, always lie, with the biggest untruths going to the parties I’d never support in a million years
exit poll, always lie, none of their business, and the impatient sods will get the real answer that matters in a few hours anyway (or sometimes if they ask how I voted, reply with a stupid comment like “oh I put an X on the paper with the pencil they supplied”)
questionnaire, approximate truth maybe with some exaggeration, but they’re a waste of time anyway since they’re more often than not self-confirming statistics, and obvious what they are trying to confirm rather than disprove