B$.$ Based on the GEO Overview, list at least $3$ entities that are defined in GEO database schema. Create a data dictionary for each of these entities. Each data dictionary should contain:

Attribute name,

Datatype,

Constrains,

Whether this attribute is primary key or foreign key

Description.

If some information that is not available on the GEO website $($e$.$g$.,$ primary and foreign keys$),$ use your best guess to fill out the data dictionaries.