Two slabs with square cross section of different materials \((1, 2)\) with equal sides \((l)\) and thickness \(d_1\) and \(d_2\) such that \(d_2 = 2d_1 \) and \(l > d_2.\) Considering lower edges of these slabs are fixed to the floor, we apply equal shearing force on the narrow faces. The angle of deformation is \(\theta_2 = 2\theta_1.\) If the shear moduli of material \(1\) is \(4 \times 10^9 \text{ N/m}^2 , \) then shear moduli of material \(2\) is \(x \times 10^9~ \text{N/m}^2 ,\) where value of \(x\) is:
1. \(1\)
2. \(2\)
3. \(5\)
4. \(6\)