Final answer:
The most prominent type of weathering in a sedimentary environment is mechanical weathering from a current, which includes the physical disintegration of rocks without chemical changes. Option number a is correct.
Step-by-step explanation:
The question asks about the most prominent type of weathering in a sedimentary environment. Among the options given, mechanical weathering from a current is most likely to be the prominent process in a sedimentary environment where particles are transported and deposited by water or wind. This process is a form of physical weathering where rocks are broken down without any change in their chemical composition, primarily through the action of water, which can carry sediments to new locations where they accumulate and eventually form sedimentary rocks.
Dissolution, frost wedging, and hydrolysis represent chemical weathering processes, which also play a role in breaking down rocks but involve a change in the rock's chemical composition. However, these processes are often less dominant in active sediment-transporting environments unless specific conditions such as freezing temperatures or highly acidic water are present.