The correct option is A MRI
To perform a study, the patient is positioned within a MRI scanner which forms a strong magnetic field around the area to be imaged. In most medical applications protons (hydrogen atoms) in tissues containing water molecules are used to create a signal that is processed to form an image of the body. First energy from an oscillating magnetic field is temporarily applied to the patient at the appropriate resonant frequency. The excited hydrogen atoms emit a radio frequency signal which is measured by a receiver coil.