To solve this problem, we need to understand why it is easier for a small animal to run uphill compared to a large animal. Let's analyze each option:$\newline \bullet$Option 1: It is easier to carry a small body weight.$\newline$ - While smaller animals do have less body weight to carry, this is not the primary reason for their ease in running uphill.$\newline \bullet$Option 2: Smaller animals have a higher metabolic rate.$\newline$ - Smaller animals generally have a higher metabolic rate, which means they can produce energy more quickly.$\newline$ - This higher metabolic rate allows them to sustain intense physical activities like running uphill more efficiently.$\newline$