The correct answer is: B. white light
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms’ activities. This chemical energy is stored in molecules of the sugar, glucose.
The process of photosynthesis can be summarized by the following chemical equation:
$$6\text{CO}2 + 6\text{H}_2\text{O} + \text{light energy} \to \text{C}_6\text{H}{12}\text{O}_6 + 6\text{O}_2$$
As you can see from the equation, six molecules of carbon dioxide and six molecules of water are used to produce one molecule of glucose and six molecules of oxygen. The light energy required for this reaction comes from sunlight.
The rate of photosynthesis depends on a number of factors, including the intensity of the light, the wavelength of the light, and the temperature. In general, photosynthesis takes place faster in brighter light and in light with a shorter wavelength.
White light is a mixture of all the colors of the visible spectrum. Each color of light has a different wavelength, with red light having the longest wavelength and violet light having the shortest wavelength.
Experiments have shown that photosynthesis takes place faster in white light than in any other color of light. This is because white light contains all the colors of light, including the colors that are most effective for photosynthesis.
Red light is the least effective color of light for photosynthesis. This is because red light has the longest wavelength, and longer wavelengths of light are less effective at stimulating photosynthesis.
In darkness, there is no light energy available for photosynthesis. Therefore, photosynthesis does not take place in darkness.