Final answer:
Rivers and streams contain the smallest percentage of all freshwater, with only about 2% of surface freshwater, which is significantly less compared to glaciers and groundwater.
Step-by-step explanation:
The freshwater source with the smallest percentage of all freshwater is rivers and streams. When looking at the distribution of Earth's water, it is important to note that the majority of freshwater is trapped in ice caps and glaciers, which account for 68.7% of all freshwater. In contrast, groundwater makes up 30.1% of freshwater. Surface water, which includes rivers and streams, represents just a little over 1.2% of all freshwater. Specifically, rivers account for only about 2% of surface freshwater. Therefore, among the options provided, rivers and streams hold the least amount of freshwater.