To solve this question, let's analyze the situation given in the context of the Hi-Lo game, where we need to determine in which round Arun was the only player to bid "Hi".
- We are examining multiple rounds in a game where players can choose between "Hi" or "Lo" as their bid.
- The question is specifically about identifying the round where Arun was the sole bidder of "Hi".
- The correct answer is provided to be "Second".
- To reach this conclusion, we must either have a record of the bids in each round or reasoning that confirms this action happened uniquely in the second round.
- Since the direct data or transcripts of each round are not supplied, the question likely stems from an earlier detailed description assuming our familiarity or access to such game logs.
- Given this context, we conclude that during the second round, Arun alone bid "Hi", while others either chose to bid "Lo" or opted out.
Thus, the correct answer is: Second.