Final Answer:
The stopper color that identifies a tube used for coagulation testing is light-blue. Option C is the answer.
Step-by-step explanation:
In laboratory settings, the color of tube stoppers often corresponds to the type of blood collection and the tests to be conducted. The light-blue stopper indicates a tube specifically designed for coagulation testing. Coagulation tests assess the blood's ability to clot, providing crucial information about the coagulation system.
The use of a standardized color-coding system enhances efficiency and accuracy in the laboratory, helping healthcare professionals easily identify the intended tests for each blood sample. Green, lavender, and red stoppers typically represent tubes used for different types of blood tests, such as chemistry, complete blood count, and blood typing, respectively.
Option C is the answer.