A "loaded question" is a question that contains a presumption or an assumption that may not be accepted by all respondents, potentially leading them to feel trapped or pressured regardless of how they answer.
Among the options provided, the question "Do you prefer this beloved fantasy series or that less acclaimed mystery novel?" is an example of a loaded question. It assumes that the fantasy series is beloved (which could imply that there is a reason to prefer it) and that the mystery novel is less acclaimed, thus framing the response in a way that elicits a particular kind of answer.
The other two questions do not contain assumptions in the same way.