Final answer:
The hard problem of consciousness refers to the challenge of explaining how and why the brain produces conscious awareness.
Step-by-step explanation:
The answer to this question is c) Hard problem of consciousness. The hard problem of consciousness refers to the challenge of explaining how and why the brain produces conscious awareness. While neuroscience has shown that alterations in brain functions can affect consciousness, the underlying mechanisms and processes by which the brain generates conscious experience are still not fully understood.