To solve this problem, we need to identify the correct taxonomic order for a horse. Let's analyze the options:$\newline \bullet$Option 1: Perissodactyla - This is the order to which horses belong. It includes odd-toed ungulates, such as horses, rhinos, and tapirs.$\newline \bullet$Option 2: Caballus - This is part of the scientific name for the domestic horse, Equus caballus, where "caballus" is the species name.$\newline \bullet$Option 3: Ferus - This is part of the scientific name for the wild horse, Equus ferus, where "ferus" is the species name.$\newline \bullet$Option 4: Equidae - This is the family to which horses belong, including zebras and donkeys.$\newline$The correct order for a horse is Perissodactyla, which corresponds to Option 1.