Related to the Kerberos protocol, how many information the Key Distribution Center, at any given time, needs to store? Select the correct answer below, where:

Key per each subject/object is like, for example: KA Key per each couple of subjects/objects is like, for example: KAB Its own key is: KKDC

a- One key to rule them all, one key to find them, one key to bring them all and in the darkness bind them

b-One key per each subject/object in the network, plus one key per each couple of subjects/objects, plus its own key

c-One key per each subject/object in the network plus its own key

d-Only its own key