Final answer:
The stream with a velocity of 0.05 cm/s can carry clay, which is the smallest and lightest sediment type and can be transported by slow-moving water.
Step-by-step explanation:
The largest sediment that can be carried by a stream with a velocity of 0.05 cm/s is clay. This is because clay particles are very small and lightweight, and they can be transported by even the slowest moving water. In geological terms, sediment transport is heavily influenced by the velocity of the moving water, with larger sediments like pebbles requiring much faster currents to be moved.
Considering that clay particles have a size of less than 3.9 μm, they can easily be suspended and transported by slow-moving water. Silt particles range from 3.9 μm to 63 μm, and they also require relatively slow currents to be moved, compared to larger sediment sizes like sand and pebbles. Since the question specifies a velocity that is very low, we can conclude that larger sediments such as sand and pebbles would not be transported by this slow velocity and, therefore, the correct answer is clay, which can remain suspended and be moved over extended periods even at such low velocities.