Step 1: Understand the application of each item.
- **Rotary atomizer (A)** is used in atomization processes, which generally relate to **centrifugal energy (2)**.
- **Relative volatility (B)** is crucial in **distillation (3)** processes.
- **Pneumatic nozzle (C)** utilizes **kinetic energy (1)** for atomizing or injecting fluids.
- **Selectivity (D)** is a term used in **liquid-liquid extraction (4)** to describe the preference for one solute over another in separation processes.
Final Answer: \[ \boxed{A - 2, B - 1, C - 3, D - 4} \]
Match the LIST-I with LIST-II 
Choose the correct answer from the options given below: