Data Model:

[Anthony]

I'm struggling on whether or not to implement GroupItem (below) with
two separate models, or with one model that has a distinguishing key:

Given:
class ParentGroup:
    a group of values represented by class GroupItem

class ChildGroup:
    a group of values represented by class GroupItem
    foreign-key to ParentGroup (many Children sum to one Parent)

Option A:
class GroupItem:
    foreign-key to ParentGroup
    foreign-key to ChildGroup
    GroupItemType in (ParentItem, ChildItem)
    value
    value-type

Option B:
class ParentGroupItem
    foreign-key to ParentGroup
    value
    value-type

class ChildGroupItem
    foreign-key to ChildGroup
    value
    value-type

What are my considerations when making this decision?

Thanks!