Answer:
a. in roentgens per hour
Explanation:
Exposure rate is the ratio of radiation exposure per unit of time. It is often used to measure radiation fields in the environment of a radioactive facility for exposure prevention and control. Exposure rate is generally expressed as per hour roentgens (R / h) used for X-ray or Gamma in air.
The röntgen or roentgen (R) is a unit of exposure to ionizing radiation. The name was given as a tribute to the German physicist Wilhelm Conrad Röntgen (or Roentgen) (1845-1923) who discovered X-rays.
