The correct answer is option 3 - Polar regions. The polar regions, including the Arctic and Antarctic, receive very little rainfall throughout the year. This is mainly due to the extremely cold temperatures and the presence of ice and snow which prevent the formation of rain clouds. Instead of rainfall, these regions experience snowfall which contributes to the accumulation of snow and ice. The lack of significant rainfall in the polar regions also affects the availability of liquid water for plants and animals. It is important to note that while some areas in Central Europe, Central North America, and Sub-Saharan Africa may experience seasonal variations in rainfall, they still receive rainfall at some point during the year, unlike the polar regions.