A machine of mass $\text{100 kg}$ is subjected to an external harmonic force with a frequency of $\text{40 rad/s}$. The designer decides to mount the machine on an isolator to reduce the force transmitted to the foundation. The isolator can be considered as a combination of stiffness $\text{(K)}$ and damper (damping factor, $\xi$) in parallel. The designer has the following four isolators:​​​​​​​

1. $\text{K = 640 kN/m}$, $\xi =0.70$
2. $\text{K = 640 kN/m}$, $\xi =0.07$
3. $\text{K = 22.5 kN/m}$, $\xi =0.70$
4. $\text{K = 22.5 kN/m}$, $\xi =0.07$

Arrange the isolators in the ascending order of the force transmitted to the foundation.

1. $1-3-4-2$
2. $1-3-2-4$
3. $4-3-1-2$
4. $3-1-2-4$