Final answer:
In Salesforce, a single object can have up to 2 Master-Detail relationships. These relationships dictate behaviors like record deletion and security from the master object to the detail object.
Step-by-step explanation:
The limit of Master-Detail relationships per object in Salesforce is Option 2: 2. This means that on a single object, you can have up to two Master-Detail relationships. A Master-Detail relationship is a parent-child relationship in which the master (parent) object controls certain behaviors of the detail (child) object, such as record deletion and security.