$102.$ Critical solution temperature $($or the con$-$solute temperature$)$ for partially miscible liquids $($e$.$g$.,$ phenol$-$water$)$ is the minimum temperature at which

A homogeneous solution $($say of phenol water$)$ is formed

Mutual solubility of the two liquids shows a decreasing trend

Two liquids are completely separated into two layers

None of these