ICF stands for International Classification of Functioning, Disability and Health. It is a framework that describes and organizes information on functioning and disability. Active health aging is divided into: Health body functions and body structures; activities; and participation. Under activities are the contextual factors; Environmental and personal.
Environmental factors is not a part of the ICF model. The correct option among all the options that are given in the question is the first option or option "A". The other three options that are given in the question, like participation, activities and persistence are all part of the ICF model. The full form of ICF is International Classification and Functioning.
The Sun is a main - sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. In its core, the Sun fuses 620 million metric tons of hydrogen each second.
Solar radiation has a lower intensity in polar regions because the angle at which solar rays hit the Earth is not as direct as at the Equator. Another effect is that sunlight has to go through more atmosphere to reach the ground.