Radiology Practice Test

The grain size/crystals on a film directly affect its speed. The larger the grains, the faster the film will be. So Option B is the correct answer. Option A is incorrect because the size of the grains and the speed are inversely related. Option C is also incorrect because the term "medium-sized" is ambiguous and does not give a definitive answer about the relationship between grain size and speed. Option D is incorrect because, as previously mentioned, grain size does play a role in the speed of a film.