Answer
A. Water
Work Step by Step
On the water phase diagram, we can see that sublimation temperature for a pressure just below 0.006 atm is slightly higher than 0$^{\circ}C$. This is higher than water's melting temperature for pressures of at least 1 atm (0$^{\circ}C$ or higher). We cannot say the same when looking at carbon dioxide phase diagram.
