The Phase Diagram for CO₂ Is Given Below

The phase diagram for CO₂ is given below .
The triple point is at 5.1 atm and 217 K.
What happens if carbon dioxide at 50C and 25 atm is suddenly brought to 1 atm?

A) The liquid and solid are in equilibrium.
B) The solid melts.
C) The solid and vapor are in equilibrium.
D) The solid vaporizes.
E) The solid remains stable.