Which of the following is true about top - soil ?

Correct option is B

The correct answer is (b).
Explanation
Topsoil is the uppermost layer of soil and is rich in humus and nutrients. It provides shelter to many living organisms such as earthworms, insects, and small animals. These organisms help in maintaining soil fertility and structure.
Additional Information
• Option {a} is incorrect because topsoil retains a good amount of water due to humus content. • Option {c} is incorrect because roots of big plants extend into subsoil layers as well. • Option {d} is incorrect because topsoil is usually dark in colour and rich in humus and minerals.