Often, building a groin or "dam" sticking out into the water from a coast in a region where longshore drift is moving sand from "upstream" to "downstream" only partially solves the problem for which the groin was designed, because: a. sediment is eroded on both sides of the groin. b. sediment is eroded upstream of the groin and deposited downstream of the groin. c. sediment is deposited on both sides of the groin. no change occurs in sediment. d. sediment is deposited upstream of the groin but eroded downstream of the groin.

Sediment is eroded on both sides of the groin.

Option A

Explanation:

While building a dam, sediments which are the small particles of the rocks that have been eroded, they are present on both sides of the dam and they get eroded even more.

Water coming from the coast is the reason why the rocks erode away and form sediments on both the sides of the rock and sometimes also leads to problems like soil erosion harming that particular piece of land for cultivation and for agriculture purposes because of loosing of fertility of that land.