Which of the following options is/are true for glass transition temperature $\mathrm{T}_{\mathrm{g}}$ ?
- Above $\mathrm{T}_{\mathrm{g}}$, glass transforms from an amorphous solid to a viscous liquid.
- $\mathrm{At}_{\mathrm{g}}$, glass transforms from an amorphous solid to a crystalline solid.
- $\mathrm{T}_{g}$ is dependent on the heating rate.
- Below $\mathrm{T}_{\mathrm{g}}$, nucleation and growth takes place in glass.
