What is the appropriate question to ask about preferred timing?

The answer is appropriate because it directly addresses the individual’s preference regarding timing. The phrasing "When would you rather go?" invites a specific response about their preferred time, allowing for a discussion about options and their availability. This type of question encourages the person to express their choice and feelings toward a particular time, making it an optimal way to inquire about preferences.

In contrast, the other options do not focus on preferences for timing in the same way. Asking for the current time, for example, is a factual request with no implication of personal preference. Inquiring about how long something takes relates more to duration rather than preference regarding when to start or partake in an activity. Lastly, suggesting an immediate departure, as in asking if they can leave now, does not allow for any input on when the individual would prefer to go; it assumes an urgent need to act without considering their personal timing preferences.