This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Magnetic Resonance Imaging, Subject name: Radiology
Gyromagnetic propey of Hydrogen nucleus is used in 
Select and explain. 
A. USG, B. PET, C. CT, D. MRI
D: MRI
Answer: D: MRI 
Explanation: MRI is based on Gyromagnetic propey of H+ ions, Protons. ULTRASOUND is based on Pulse echo principle and Piezoelectric effect. CT SCAN is based on Linear attenuation of X rays.