You are developing a combiner that takes as input Text keys, IntWritable values, and emits Text
keys, IntWritable values. Which interface should your class implement?

A.
Combiner <Text, IntWritable, Text, IntWritable>

B.
Mapper <Text, IntWritable, Text, IntWritable>

C.
Reducer <Text, Text, IntWritable, IntWritable>

D.
Reducer <Text, IntWritable, Text, IntWritable>

E.
Combiner <Text, Text, IntWritable, IntWritable>