Transform 'He has been here before' into a question form that retains its original context.

The choice that best transforms the statement "He has been here before" into a question while retaining the context is "Has he been at this place before?"

This option keeps the original meaning intact, as it directly inquires whether the individual has had prior experience at the same location, just as the original statement does. It maintains the present perfect structure, indicating relevance to both past experience and the present context, which is crucial for conveying the same idea as the original sentence.

Other options may alter the context or meaning slightly. For example, "Has he ever been here?" introduces a broader timeframe and could imply a different nuance than merely asking about prior visits to this specific location. Similarly, "Has he been here previously?" while still quite close, can be viewed as slightly less informal and might sound less natural casual conversation. Lastly, "Was he here before?" changes the tense and aspect, leading to a focus on a specific occasion rather than ongoing relevance, and thus strays from the same semantic grounding.