Answer: DataFrame.withColumnRenamed()

The correct answer is B. DataFrame.withColumnRenamed() is the method used to rename an existing column in a DataFrame. The other options are incorrect: A (renamedColumn) does not exist, C (wlthColumn) is a typo and should be withColumn(), which can replace a column's data but not rename it directly. D (col()) refers to a column object, and E (newColumn()) is not a valid method.

Author: LeetQuiz Editorial Team