Final answer:
The primary concern associated with the Generic Subjective Continuity (GSC) theory is existential continuity denial.
Step-by-step explanation:
The primary concern associated with the Generic Subjective Continuity (GSC) theory is b) Existential continuity denial. GSC theory suggests that there is no continued existence or continuity of consciousness beyond the physical body. It denies the idea of a soul or any form of existence after death. This theory is not well supported by evidence and is considered speculative.