In the Reducer, the MapReduce API Provides You with an Iterator

Multiple Choice

In the reducer, the MapReduce API provides you with an iterator over Writable values. What does calling the next () method return?

A) It returns a reference to a different Writable object time.
B) It returns a reference to a Writable object from an object pool.
C) It returns a reference to the same Writable object each time, but populated with different data.
D) It returns a reference to a Writable object. The API leaves unspecified whether this is a reused object or a new object.
E) It returns a reference to the same Writable object if the next value is the same as the previous value, or a new Writable object otherwise.