The correct answer is: B. Carbon dioxide
Dry ice is the solid form of carbon dioxide. It is a white solid that sublimes at -78.5 °C (-109.3 °F), meaning it changes directly from a solid to a gas without passing through a liquid state. Dry ice is often used as a refrigerant, as it is very cold and does not leave any residue. It is also used in theatrical productions and special effects, as it creates a fog-like effect when it sublimates.
Air is a mixture of gases, including nitrogen, oxygen, argon, carbon dioxide, and water vapor. It is not a solid, so it cannot be the solid form of carbon dioxide.
Nitrogen is a gas at room temperature and pressure. It is not a solid, so it cannot be the solid form of carbon dioxide.
Water is a liquid at room temperature and pressure. It is not a solid, so it cannot be the solid form of carbon dioxide.