Final answer:
In the context of developing dental radiographs, hydroquinone develops the black tones while Elon brings out the white tones, making option 1: Black, white the correct answer.
Step-by-step explanation:
The hydroquinone in the developer brings out the black tones, whereas the Elon (Metol) in the developer brings out the white tones on a dental radiograph. Therefore, option 1: Black, white is the correct answer. When developing a dental radiograph, hydroquinone works to develop the silver halide crystals in the radiographic film that have been exposed to radiation into metallic silver, resulting in the black areas of the image. Elon, on the other hand, tends to be more active in the less-exposed areas, hence enhancing the lighter or white parts of the image, thus providing the necessary contrast essential in dental radiographs.