Question

select the correct answer. the ground beneath the nelson’s house is beginning to sag and sink. which of the following is a possible explanation? a. the groundwater has been exhausted. b. the nelsons have built their home on a continental plate. c. there is too much salt in the soil. d. leaching is causing the soil to weaken.

Explanation:

To determine the correct answer, we analyze each option:

• Option A: When groundwater is exhausted (over - pumped), the soil and rock above lose the support that the water provided. This can cause the ground to sag and sink as the pore spaces collapse without the water to hold them open.
• Option B: Building on a continental plate does not inherently cause the ground to sag and sink. Continental plates are large, stable (in terms of this kind of subsidence) tectonic features for the most part, and building on them is common without this specific issue.
• Option C: Having too much salt in the soil (salinity) generally affects plant growth and soil structure in terms of water - holding capacity for plants, but it does not directly cause the ground to sag and sink in the way described.
• Option D: Leaching is the process of dissolving and carrying away minerals from the soil. While it can affect soil fertility and structure, it is not a primary cause of ground sagging and sinking like groundwater exhaustion is.

Answer:

A. The groundwater has been exhausted.