Which of the following is true of wetlands?
A. Wetlands help prevent flooding, but they do not help recharge ground water
B. Wetlands slow erosion, help recharge groundwater, and help prevent flooding
C. Wetlands slow erosion and help recharge groundwater, but they have no effect on flooding
D. Wetlands speed up erosion and help prevent flooding

The wetlands are known to prevent flooding and slows erosion while it helps in recharging the groundwater.

Option B

Explanation:

The wetlands are lands which has an accumulation of water all the time in particular regard to the time that it is may be permanent or periodical with season. Wetlands are swamps, marshlands, boglands and others.

As they are already holding up water, it effectively slower the rate of erosion due to restricted movement by soothing the harshness of the soil to erode with suspension of soil particulate. This eventually helps recharge the groundwater and overall when seen in conclusive terms, prevents the area from flooding conditions.

B. Wetlands slow erosion, help recharge groundwater, and help prevent flooding

Explanation:

Wetlands provide values that no other ecosystem can.  These include natural water quality improvement, flood protection, shoreline erosion control, opportunities for recreation and aesthetic appreciation and natural products for our use at no cost. Protecting wetlands can protect our safety and welfare.

Wetlands function as natural sponges that trap and slowly release surface water, rain, snowmelt, groundwater and flood waters. Trees, root mats and other wetland vegetation also slow the speed of flood waters and distribute them more slowly over the floodplain. This combined water storage an braking action lowers flood heights and reduces erosion.

i don't understand. explain it clearly