Final answer:
The mind-body problem is the first issue with identity theory involving multiple realizability, challenging the correspondence between mental states and brain states.
Step-by-step explanation:
The first problem with identity theory that involves multiple realizability is captured by a) The mind-body problem. Identity theory suggests that mental states are identical to brain states. However, multiple realizability challenges this by asserting that the same mental state can be realized in different ways in different organisms, implying that there is not a one-to-one correspondence between mental states and brain states. This issue is intrinsic to the mind-body problem, as it questions how mental phenomena can consistently correspond to physical brain states given the vast diversity across individuals and species.