In the developing solution, which chemical blackens the exposed silver halide crystals?

Question

Quizplus · Accepted Answer

Hydroquinone is the chemical that blackens the exposed silver halide crystals during the developing process in photography. Sodium sulfite and sodium carbonate are developing agents that reduce the unexposed silver halide crystals to prevent them from blackening, while potassium bromide is a restrainer that prevents the development in unexposed areas.

In the Developing Solution, Which Chemical Blackens the Exposed Silver