FILL BLANK - Determine if the description is Master/Detail or Lookup: Lookup field on child is always required.
Master/Detail.
A lookup field is a type of relationship field that allows a record to be associated with another record from a different object. In a lookup relationship, the child object has a field that references the parent object.
In a lookup relationship, the lookup field on the child object is not always required. This means that the child record can exist without being associated with a parent record.
On the other hand, in a Master/Detail relationship, the detail record cannot exist without a master record. The Master/Detail relationship is a more restrictive relationship between two objects in Salesforce.
In a Master/Detail relationship, the detail object's record is always required to be associated with a master record. In a Master/Detail relationship, if the master record is deleted, all associated detail records are also deleted. This cascading delete behavior is not available in lookup relationships.
Therefore, based on the given statement, the blank should be filled with "Master/Detail" as a lookup relationship does not require the lookup field on the child object to be always required.