Correct Answer: C. – 27 C
Explanation: Cryostats are maintained at temperatures of -27 to -30 C. Cryostats are used in Mohs surgery when sectioning frozen specimens. -50 is the ideal temperature for destruction of melanocytic lesion with cryo. The boiling point of liquid nitrogen is -196 C.
Ref: Erickson QL, Clark T, Larson K, et al. Flash freezing of Mohs micrographic surgery tissue can minimize freeze artifact and speed slide preparation. Dermatol Surg 2011. 37:503-9..