Different surfaces have different albedo, which refers to the fraction of sunlight that is reflected back from a surface. The higher the albedo, the more sunlight is reflected back.

Out of the four options given, land covered with fresh snow reflects back the most sunlight as it has a high albedo. Snow has an albedo of around 80-90%, which means that it reflects back 80-90% of the sunlight that falls on it.

In contrast, sand desert has a lower albedo, around 30-40%. This means that it absorbs more sunlight and reflects back less.

Paddy crop land and prairie land also have lower albedo than snow, as they are covered with vegetation which absorbs sunlight rather than reflecting it back. However, the albedo of these surfaces can vary depending on factors such as the type of vegetation, moisture content, and season.