What term describes tiny channels or narrow grooves created on Earth's surface by water flow, which are shallow enough to be smoothed out by farming practices?

Explanation

Small, shallow water-formed channels on the ground surface that can be leveled by tillage are known as rills, which are not listed among the options. The given options refer to different types of erosion: gullies are larger and deeper channels; sheet erosion involves uniform soil removal; stream bank erosion affects riverbanks. Therefore, none of the provided answers correctly identify these small channels.