The electromagnetic spectrum

Hard

Four distinct physical processes generate different regions of the electromagnetic spectrum:

Process I: Nuclear de-excitation following radioactive decay.
Process II: Inner-shell electron transitions in a heavy metal target.
Process III: Thermal emission from an object at room temperature (300 K).
Process IV: High-frequency oscillation of conduction electrons in a metal transmitter.

Which option lists the electromagnetic waves produced by these processes in order of decreasing wavelength?

$IV\text{Process I} \longrightarrow \text{Process II} \longrightarrow \text{Process III} \longrightarrow \text{Process IV}$

$I\text{Process III} \longrightarrow \text{Process IV} \longrightarrow \text{Process II} \longrightarrow \text{Process I}$

$II\text{Process IV} \longrightarrow \text{Process III} \longrightarrow \text{Process I} \longrightarrow \text{Process II}$

$I\text{Process IV} \longrightarrow \text{Process III} \longrightarrow \text{Process II} \longrightarrow \text{Process I}$

The electromagnetic spectrum Questions