I wouldn't recommend to center the answer options. It is always better to have all radio buttons in one vertical line, as it makes it a lot easier to click.
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Provide your LS version and where it is installed (own server, uni/employer, SaaS hosting, etc.).
Always provide a LSS file (not LSQ or LSG).
Note: I answer at this forum in my spare time, I'm not a LimeSurvey GmbH employee.
in the advanced settings of your question look for "Display columns" and put the number of columns you need (I don't remember the limit allowed, maybe 7 or 9)