This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pathology
Earliest histological change in MI- 
Select and explain. 
A. Macrophage infiltration, B. Neutrophilic Infiltration, C. Waviness of fibers, D. Coagulative necrosis
C: Waviness of fibers
Answer: C: Waviness of fibers 
Explanation: The microscopic appearance also undergoes a characteristic sequence of changes Typical features of coagulative necrosis become detectable within 4 to 12 hours of infarction. "Wavy fibers" also can be present at the edges of an infarct; these reflect the stretching and buckling of noncontractile dead fibers. Sublethal ischemia can also induce intracellular myocyte vacuolization; such myocytes are ble but frequently are poorly contractile. (Robbins Basic Pathology,9th edition,pg no.383)