In This Selection Locke Sets Forth His Psychological State Theory

In this selection Locke sets forth his psychological state theory of personal identity, locating the criterion of personal identity in terms of consciousness (personality, character, and, especially, memory) . He says that personal identity consists in "the sameness of a rational being [consciousness]." This consciousness can take on different bodily forms and still preserve the same identity. It is possible for a prince to switch bodies with a cobbler, yet the prince would still be the prince.
-According to Locke, the state of being the same substance is

A) necessary for personal identity.
B) not necessary for personal identity.
C) sufficient for personal identity.
D) necessary and sufficient for personal identity.