Q. With reference to ‘Land Subsidence’ consider the following statements::
1.Subsidence is the sinking of the ground because of underground material movement. 
2.It is only caused by the anthropogenic activities.
3.Shrinking and swelling of cohesive soil is one of the reasons behind subsidence of land.
Which of the statements given above is/are correct?

[A] 1 and 3 only

[B] 1 only

[C] 1 and 2 only

[D] 1, 2 and 3

Answer: A
Notes:

Explanation –

Statement 1 and 3 are correct. Subsidence is the sinking of the ground because of underground material movement. Cohesive soils such as clay and silt are particularly likely to cause subsidence, since they shrink and swell depending on their moisture content.

Statement 2 is incorrect. Both natural and man-made activities are responsible for subsidence of land.

Source: ForumIAS