Answer: The answer is JOINT TENANCY
Explanation: What is joint tenancy?
This is a legal arrangement whereby two or more people jointly own a property, in this arrangement, all owners have equal rights and obligations to the property. When one of the owners die, that owner's stake in the property goes to the surviving owners without having to pass through the court, because of the right of survivorship.
So the type ownership between Sam and Bridget above is a Joint Tenancy.