Which of the following units does not belong to Major?

The correct answer indicates that Units 210-219 do not belong to Major. This is because Major systems typically have larger or broader numerical ranges that encompass a significant number of units, usually in the hundreds or thousands. Units categorized under Major are often associated with key operational areas or departments that require extensive coordination and resources.

In contrast, the range of Units 210-219 is much more limited, suggesting a more specific or localized group that may not align with the broader representation typically seen in Major classifications. The other choices, which include larger unit designations (1900-1999, 4100-4199, and 4300-4399), indicate they are part of more comprehensive categories often associated with higher-level operations or multi-unit functionalities consistent with Major structures.