[Solved] Dr. Ahmed wants to study the effect of university experience on anxiety before taking an exam. Dr. Ahmed needs an operational definition for anxiety. Which of the following should she use? A) a score on the Hamilton Anxiety Rating Scale B) a feeling of extreme nervousness C) the opposite of feeling relaxed D) a sense of worry Ultraviolet Radiation: A form of energy emitted by the sun, invisible to the naked eye, which can have harmful effects on human skin and eyes but is essential for the synthesis of vitamin D. Earth: The third planet from the Sun, characterized by its vast oceans, diverse ecosystems, and the presence of life, including human civilization. Fish Species: Various types of fish differentiated by genetic, morphological, and ecological characteristics, comprising a significant portion of aquatic biodiversity. Decline: A gradual decrease in quality, quantity, or significance of something, such as economic performance, population numbers, or social values.