The first dental radiograph was produced using an exposure time of

A) 0.5 second.
B) 1 minute.
C) 5 minutes.
D) 25 minutes.
E) 1 hour.

D
Explanation: A) Dr. Otto Walkhoff, a German physicist, was the first to expose a prototype of a dental radiograph. This was accomplished by covering a small, glass photographic plate with black paper to protect it from light and then wrapping it in a sheath of thin rubber to prevent moisture damage during the 25 minutes that he held the film in his mouth.
B) Dr. Otto Walkhoff, a German physicist, was the first to expose a prototype of a dental radiograph. This was accomplished by covering a small, glass photographic plate with black paper to protect it from light and then wrapping it in a sheath of thin rubber to prevent moisture damage during the 25 minutes that he held the film in his mouth.
C) Dr. Otto Walkhoff, a German physicist, was the first to expose a prototype of a dental radiograph. This was accomplished by covering a small, glass photographic plate with black paper to protect it from light and then wrapping it in a sheath of thin rubber to prevent moisture damage during the 25 minutes that he held the film in his mouth.
D) Dr. Otto Walkhoff, a German physicist, was the first to expose a prototype of a dental radiograph. This was accomplished by covering a small, glass photographic plate with black paper to protect it from light and then wrapping it in a sheath of thin rubber to prevent moisture damage during the 25 minutes that he held the film in his mouth.
E) Dr. Otto Walkhoff, a German physicist, was the first to expose a prototype of a dental radiograph. This was accomplished by covering a small, glass photographic plate with black paper to protect it from light and then wrapping it in a sheath of thin rubber to prevent moisture damage during the 25 minutes that he held the film in his mouth.