Each of the following is in the path of the x-ray beam during exposure of an intraoral dental radiograph on an adult patient. Which one, because of its relative radioresistancy is NOT considered...

Each of the following is in the path of the x-ray beam during exposure of an intraoral dental radiograph on an adult patient. Which one, because of its relative radioresistancy is NOT considered critical for dental radiography?

a. Mandible

b. Lens of the eye