Pick up the correct statement from the following.

Pick up the correct statement from the following regarding bulking of sand:

A. Bulking of sand is caused due to formation of a thin film of surface moisture

B. Fine sand bulks more than coarse sand

C. With 10% moisture content by weight the bulking of sand is increased by 50%

D. All options are correct

Correct Answer: D. All options are correct

📚 Detailed Explanation: Three Correct Bulking Statements

Why D (All options correct) is correct:

Statement	Verdict	Explanation
A. Bulking caused by thin film of surface moisture	Correct	Thin water films at particle surfaces create surface tension that holds grains apart — the fundamental mechanism of bulking
B. Fine sand bulks more than coarse sand	Correct	Fine sand has higher specific surface area → more water film effect per unit volume → greater bulking for the same moisture %
C. 10% moisture → 50% bulking	Correct	For very fine sands under certain conditions, bulking can reach up to 50% at peak moisture ranges; textbook value accepted as correct

All three statements correctly describe aspects of sand bulking behaviour.
The fundamental cause: thin moisture film → surface tension → particle separation → volume increase.