Final answer:
The term 'fresh green light' refers to a traffic signal that has just turned green, indicating it's time to proceed. It doesn't imply variations in the light's brightness or frequency. Green light in physics has a lower frequency and a longer wavelength compared to blue light and has implications in plant growth due to its absorption rates.
Step-by-step explanation:
The student has asked about a light signal that has just changed to green. The term 'fresh green light' typically refers to a traffic light that has recently changed from red to green, signaling that vehicles can proceed. It does not refer to variations in the brightness or physical properties of the light itself. Therefore, the correct answer is a. a fresh green light.
Regarding the properties and behaviors of green light in physics, it's important to know that the frequency of green light is lower than that of blue light, which means that green light has a longer wavelength than blue light. When white light shines on a yellow paper, the paper will appear yellow; however, if yellow light shines on white paper, the white paper will also look yellow. When red and green lights are projected onto a white paper, we may perceive a color that is the result of the combination of these two colors, which can sometimes be perceived as a yellowish color.
In biological contexts, such as in plant growth, green light is not as effectively absorbed by the pigment chlorophyll as other colors of light, such as red or blue. Therefore, under green light, a plant may grow tall and spindly as if it were in the dark, due to a lack of effective photosynthesis being triggered by the light.