Which Statement Best Describes the Relationship Between Superclass and Subclass

Multiple Choice

Which statement best describes the relationship between superclass and subclass types?

A) A subclass reference cannot be assigned to a superclass variable and a superclass reference cannot be assigned to a subclass variable.
B) A subclass reference can be assigned to a superclass variable and a superclass reference can be assigned to a subclass variable.
C) A superclass reference can be assigned to a subclass variable, but a subclass reference cannot be assigned to a superclass variable.
D) A subclass reference can be assigned to a superclass variable, but a superclass reference cannot be assigned to a subclass variable.