Final answer:
Sales of animals at auctions are conducted without warranty against hidden defects.
Step-by-step explanation:
In the case of sales of animals without warranty against hidden defects, the option that applies is Option 2: When the sale is at auction. Sales at auction typically do not come with warranties, as buyers have the opportunity to inspect the animals before making a bid. Therefore, it is important for buyers to thoroughly examine the animals before participating in the auction.