The dimension of dynamic viscosity is:

1. $\text{ML}^{-1} \text{T}^{-1}$
2. $\text{ML}^{-1} \text{T}^{-2}$
3. $\text{ML}^{-2} \text{T}^{-2}$
4. $\text{ML}^{0} \text{T}^{-1}$