In Python, Functions Are Treated as First-Class Data Objects

Multiple Choice

In Python, functions are treated as first-class data objects. What does this mean?

A) It means that they are considered to be global variables inside any Python code.
B) It means that the functions are given higher priority over resource access than regular chunks of code.
C) It means that functions are protected objects and are not easily imported from other modules, unless the author desires it.
D) It means that functions can be assigned to variables, passed as arguments to other functions, returned as values, and stored in data structures.