- A. KCl: KCl is used in thermoluminescent reactions, making it related to the light-emitting properties of certain compounds.
- B. KCl: KCl is also a fertilizer as it contains potassium and chlorine.
- C. KOH: KOH is essential for the sodium-potassium pump, which is crucial for cell function and active transport.
- D. KOH: KOH is an absorber of CO\(_2\) because of its basic nature and ability to neutralize CO\(_2\).
Thus, the correct matching is A-IV, B-III, C-I, D-II.