Answer the following question given this paragraph: 

Plant Responses to Light Plants have a number of sophisticated uses for light that go far beyond their ability to photosynthesize low-molecularweight sugars using only carbon dioxide, light, and water. Photomorphogenesis is the growth and development of plants in response to light. It allows plants to optimize their use of light and space. Photoperiodism is the ability to use light to track time. Plants can tell the time of day and time of year by sensing and using various wavelengths of sunlight. Phototropism is a directional response that allows plants to grow towards, or even away from, light. The sensing of light in the environment is important to plants; it can be crucial for competition and survival. The response of plants to light is mediated by different photoreceptors, which are comprised of a protein covalently bonded to a lightabsorbing pigment called a chromophore. Together, the two are called a chromoprotein.


Q: Plants can tell the time of day and time of year by sensing and using various wavelengths of what

 Choices:

- moisture

- lunar cycles

- precipitation

- sunlight

A:
sunlight
