Given below are the steps involved in the process of zone refining for removing impurities which are more soluble in the melt than solid state of the metal.

1. Impurities get concentrated at one end
2. As the heater moves forward, the pure metal crystallizes out of the melt left behind and the impurities pass to the next zone
3. A mobile heater surrounding the rod of impure metal is fixed at its one end.
4. The end is cut off.
5. The molten zone moves along with the heater which is moved forward.

Choose the correct answer from the options given below:

C, E, B, A, D

The correct order of steps involved in the process of zone refining is 3. C, E, B, A, D.

Here is a description of the steps:

1. C.  A mobile heater surrounding the rod of impure metal is fixed at its one end. The mobile heater is used to melt a small zone of impure metal at one end of the rod.
2. E.  The molten zone moves along with the heater which is moved forward. The heater is slowly moved along the rod, melting a new zone of metal and leaving behind a zone of pure metal.
3. B.  As the heater moves forward, the pure metal crystallizes out of the melt left behind and the impurities pass to the next zone. As the molten zone cools, the pure metal crystallizes out of the melt. The impurities, which are more soluble in the melt, are concentrated in the remaining molten zone.
4. A.  Impurities get concentrated at one end. The impurities are concentrated at the end of the rod where the heater started.
5. D.  The end is cut off. The end of the rod with the concentrated impurities is cut off.

Therefore, the correct order of steps involved in the process of zone refining is 3. C, E, B, A, D.