Amit's brother Ajit is a professional photographer who lives in Delhi. Once during his visit to belhi, Amit asked his brother to take him along to his studio. When they reached there, Ajit went to a dark room. This room was red in colour and made Amit think why the light used in the room was red and not any other colour. Ajit told him that there is a scientific phenomenon behind the red colour. Below are given the options which might be the explanation given by Ajit to Amit to make him understand the concept behind the use of red light. Choose the most suitable option.

• A. Red colour makes a beautiful ambience that is soothing to the eyes.
• B. Red colour has the highest wavelength and thus the lowest frequency. This also means that it has the least energy which does not hinder with the process of developing photographs.
• C. Red colour has the energy which makes the process of developing photographs easy.
• D. All of these.