The Poisson’s ratio is defined as

1. $\begin{vmatrix} \dfrac{\text{axial stress}}{\text{lateral stress}} \end{vmatrix} \\$
2. $\begin{vmatrix} \dfrac{\text{lateral strain}}{\text{axial strain}} \end{vmatrix} \\$
3. $\begin{vmatrix} \dfrac{\text{lateral stress}}{\text{axial stress}} \end{vmatrix} \\$
4. $\begin{vmatrix} \dfrac{\text{axial strain}}{\text{lateral strain}} \end{vmatrix}$