Which of the following will add a key to the dictionary only if it does not already exist in the dictionary ?

1. fromkeys( )
2. update( )
3. setdefault( )
4. all of these

Which of the following will create a dictionary with given keys and a common value ?

1. fromkeys( )
2. update( )
3. setdefault( )
4. all of these

Which of the following can be used to delete item(s) from a dictionary?

1. del statement
2. pop( )
3. popitem( )
4. all of these

Which of the following will raise an error if the given key is not found in the dictionary ?

1. del statement
2. pop( )
3. popitem()
4. all of these