Object Relationships Not Allowed

B.

In Salesforce, objects can be related to each other in various ways such as Master-Detail, Lookup, and many-to-many relationships. These relationships define how data is stored and how records can be accessed and manipulated.

A Master-Detail relationship is a parent-child relationship where the parent object controls certain behaviors of the child object. For example, if the parent record is deleted, all related child records are also deleted. In contrast, a Lookup relationship is a non-hierarchical relationship where one object has a reference to another object.

Now, let's examine each option in the given question and determine whether it's a valid object relationship or not:

A. Standard object as the "master" and a custom object as the detail This relationship is allowed in Salesforce. A standard object can be the parent/master object, and a custom object can be the child/detail object in a Master-Detail relationship.

B. Custom object as the master" and a standard object as the detail This relationship is also allowed in Salesforce. A custom object can be the parent/master object, and a standard object can be the child/detail object in a Master-Detail relationship.

C. Custom object as a lookup to a standard object This relationship is also allowed in Salesforce. A custom object can have a lookup field that references a standard object. This creates a non-hierarchical relationship between the custom object and the standard object.

D. Custom object as a lookup to a custom object. This relationship is allowed in Salesforce. A custom object can have a lookup field that references another custom object. This creates a non-hierarchical relationship between the two custom objects.

Therefore, all of the object relationships listed in the question are allowed in Salesforce, and the correct answer is none of the above.