The correct answer is option 1 - pressure on the sand is decreased by increasing the area of the surface in contact. Camels have evolved to have flat feet, which helps them walk easily in sandy deserts. When a camel walks, the weight of its body is spread out over a larger area due to the flatness of its feet. This increased surface area reduces the pressure exerted on the sand beneath the feet. As a result, the camel`s feet sink less into the soft sand, allowing it to move more easily and efficiently. This adaptation is particularly advantageous in desert environments where the sand can be difficult to traverse. So, the flat-footed structure of camels helps decrease the pressure on the sand, making it easier for them to walk in sandy deserts.