Correct Answer - Option 2 : More volume reduction occurs in clay

__Explanation__

1) Bulk Unit weight γb: It is defined as the ratio of the total weight of soil to the total volume of the soil mass.

\({\gamma _b} = \frac{W}{V} = \frac{{{W_s} + {W_w}}}{{{V_s} + {V_w} + {V_a}}}\)

As it is givem that if unit weight is increased by 10% (i.e.) it is signifying the weight of water is increased or Volume of water or air or Volume of voids got decreased.

(Weight of solids remains unchanged)

As the option relates to Volume.

Definitly volume reduction takes place.

Comparitively to Sand more Volume reduction takes place in clay.

**Lets consider Montmorillonite clay (Expansive soil) It expands as well as shrinks more compared to sand.**