Correct Answer - Option 2 :
a - 3, b - 1, c - 4, d - 2
Explanation:
Soil and rock classification (according to VOB – Part C: General technical specifications in construction contracts (ATV) – earthworks, ATV DIN 18300
Soil and rock classification
Class 1 - Top Soil
Class 2: Flowing Soil
Class 3: Easily loosened soil types
Class 4: Moderately hard-to-loosen soil types
Class 5: Hard-to-loosen soil types
Class 6: Easily loosened rocks and comparable soil types
Class 7: Hard-to-loosen rock