What is the correct abbreviation for Centigrade?

The correct abbreviation for Centigrade is "C." This designation is widely recognized in scientific and medical contexts to represent degrees Celsius, a temperature scale where water freezes at 0 degrees and boils at 100 degrees under standard atmospheric conditions. This scale is commonly used globally and is essential in healthcare for measuring body temperature and other temperature-related measurements.

The other abbreviations listed refer to different temperature scales: "F" stands for Fahrenheit, "K" stands for Kelvin, and "R" is used for Rankine. Each of these scales has its own applications and significance but does not pertain to Centigrade. Understanding these distinctions aids in accurately interpreting temperature readings in various situations, particularly in medical and scientific fields.