Of the incident solar radiation, what is the percentage of photosynthetically active radiation (PAR)?

The correct option is 2-10%.

Step-by-Step Explanation:
Solar radiation reaching the Earth's surface contains a wide spectrum of electromagnetic waves, only some of which can be utilized by photosynthetic organisms.
1. Photosynthetically Active Radiation (PAR): Of the total incident solar radiation, less than 50% consists of radiation that plants can use for photosynthesis. This range (spectral range of 400 nm to 700 nm) is known as Photosynthetically Active Radiation (PAR).
2. Capture of Energy by Plants: Even though less than 50% of solar radiation is PAR, plants and photosynthetic autotrophs do not absorb all of it. They capture only about 2% to 10% of this PAR to carry out photosynthesis and synthesize organic matter.
3. Ecosystem Sustainability: This small portion (2-10%) of energy captured by green plants is the primary source of energy that sustains the entire living world, driving the energy flow through all trophic levels in an ecosystem.