Match the following industrial processes with the catalysts used:

Cracking of hydrocarbons – Fe
Each process is paired with its appropriate catalyst, enhancing the reaction's efficiency. For example, Ostwald's process uses \( \text{CuCl}_2 \) to produce nitric acid from ammonia.
Consider the following compounds. Arrange these compounds in a n increasing order of reactivity with nitrating mixture. The correct order is : 