A key of type ___________ is generated which is used later to join ngrams with their heads and tails in the reducer phase.

A key of type ___________ is generated which is used later to join ngr

1.	A key of type ___________ is generated which is used later to join ngrams with their heads and tails in the reducer phase.
A.	GramKey
B.	Primary
C.	Secondary
D.	None of the mentioned
Answer» B. Primary