Concept:Clayey soil changes its volume with moisture.
It swells when wet and shrinks when dry.
So any statement saying the opposite is false.
Explanation:Clayey soil contains very fine particles that are tightly packed.
These particles absorb water and expand.
Therefore, clayey soil swells when wet and shrinks when dry.
The statement given in option A says exactly the reverse.
It claims that clayey soil swells when dry and shrinks when wet.
This is incorrect.
When dry, clayey soil loses moisture and becomes hard and compact.
It is difficult to plough when dry.
It also has high water retention.
Thus options B, C, and D are true statements.
Only option A is not true.
Answer:A. swells when dry and shrinks when wet.