Which one of the following is termed as 'Dry ice'?

Dry ice is the common name for the solid-state of carbon dioxide (CO2). Unlike regular ice, which is solid water (H2O) found in polar regions like Antarctica [1][2], dry ice does not melt into a liquid at standard atmospheric pressure. Instead, it undergoes sublimation, transitioning directly from a solid to a gas. While carbon dioxide is a trace gas in Earth's atmosphere, it can be synthesized into solid crystals or 'ice' under specific temperature and pressure conditions, a process studied in material science and planetary observations of bodies like Mars. In everyday applications, dry ice is used as a cooling agent because it is colder than water ice and leaves no liquid residue. It is distinct from the ice sheets of Greenland or Antarctica, which consist of accumulated snow and frozen water [2].

Sources

1. [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 12: Major Crops and Cropping Patterns in India > Biotic: Living > p. 113
2. [2] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 11: World Climate and Climate Change > Ice Cap Climate (EF) > p. 94