Which one is correct?

Which one of the following Python statements can be used to create the dataframe x ? Dataframe x : AaNaNbNaNcNaN alpha vantage pd. DataFrame(index =[ ' A '] , columns =[ ' a ', ' b ', ' c ' ] ) pd.DataFrame(index =[a, ', ' 'c' ], columns='A') pd.DataFrame(index =[ ' a ', ' b ', ' c ' ], columns =[A])