This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
A child was taken for CECT Chest and contrast was injected :  the child had swelling which gradually increased. There is numbness. There is a pain on passive extension of fingers. He is not allowing you to touch the arm. Pulse was present. What will you do? 
Select and explain. 
A. High Dose Prednisolone, B. Arterial Thrombectomy, C. Immediate Fasciotomy, D. Antihistamines / Anticoagulants
C: Immediate Fasciotomy
Answer: C: Immediate Fasciotomy 
Explanation: The child is having Compartment syndrome due to extravasation of contrast. This is a medical emergency and immedicate fasciotomy needs to be done to prevent tissue necrosis.