Correct Answer : count()
Explanation : count() is an action operation in PySpark. It returns the number of elements in an RDD. Other action operations in PySpark include collect(), reduce(), take(), and foreach().
Correct Answer : pyspark.sql.DataFrame
Explanation : pyspark.SQL.DataFrame represents a set of named columns and distributed data.
Correct Answer : pyspark.sql.SparkSession
Explanation : DataFrame and SQL functionality are accessed through pyspark.sql.SparkSession.
Correct Answer : Column
Explaination : A UDF extends Spark SQL's DSL vocabulary for transforming DataFrames by defining a new column-based function.