Silver bromide (AgBr) is used in photographic films because silver bromide islight sensitive.
Silver bromide (AgBr) is a colorless coating on a photographic film that decomposes and converted to elemental silver when exposed to the light and causes the film to darken.
Hence, the correct answer is "D. Silver bromide".
For many chemical reactions, the actual yield is usually less than the theoretical yield. This is due to possible loss in the process or inefficiency of the chemical reaction.