Radiation exposure occurs in all except
B i.e. MRI Radiography use X-rays, which are ionizing radiation.Q Thermography or thermal imaging is a type of infrared imagine. Thermographic cameras detect radiation in the infrared range of the electromagnetic spectrum (roughly 900-14,000 nanometer or 0.9-14 um) MRI & USG has no radiation riskQ.
CT Scan, PET scan
MRI
Fluroscopy
Plain X-Ray