Answer: DataFrame.drop_duplicates(subset = "all")

The question asks which operation fails to return a DataFrame with no duplicate rows. The methods `DataFrame.dropDuplicates()`, `DataFrame.distinct()`, `DataFrame.drop_duplicates()`, and `DataFrame.drop_duplicates(subset = None)` are all valid and will return a DataFrame with no duplicate rows by considering all columns. However, `DataFrame.drop_duplicates(subset = 'all')` is problematic because 'all' is not a valid subset parameter value; it expects a list of column names. This would cause the operation to fail or not work as intended, thus not guaranteeing a DataFrame with no duplicate rows.

Author: LeetQuiz Editorial Team