A. It is used for object serialization
B. It is used for object de-serialization
C. change the string value to number
D. extract the list element in simple variable

Solution

B. It is used for object de-serialization

Explanation

Unpickling is the process of deserializing a serialized object, which means converting a previously serialized (pickled) object back into its original form in Python. Serialization is the process of converting a data structure or object into a format that can be easily stored and later reconstructed. Pickling is the term used in Python to describe the serialization process.