I Answer Key & Explanations Correct Answer: C) Vital capacity ✅ Explanation: Vital capacity is the sum of Tidal Volume, Inspiratory Reserve Volume, and Expiratory Reserve Volume. It represents the maximum exchangeable volume of air. Incorrect Options: Total lung capacity (A) includes residual volume which cannot be breathed out. Expiratory capacity (B) and Inspiratory capacity (D) only measure volumes relative to normal (not forced) breathing. Correct Answer: C) Cycling ✅ Explanation: A conditioned reflex is a learned response. Cycling is a motor skill that becomes automatic through practice. Incorrect Options: Options A, B, and D are innate or simple reflexes that occur naturally without learning. Correct Answer: D) Frequency ✅ Explanation: For electrons to be emitted, the energy of a photon ( 𝐸 =