Which of the following accurately describes the release of IGF-1 and its manifestation in response to resistance training?
a) IGF-1 is released from the liver and directly acts on skeletal muscle, leading to immediate hypertrophy.
b) IGF-1 is primarily released from the pancreas and exerts its effects on bone density rather than muscle mass.
c) IGF-1 is secreted by muscle cells themselves in response to resistance training, promoting muscle growth and repair.
d) IGF-1 is released by the brain and influences the central nervous system, indirectly impacting muscle adaptation.