Final answer:
Muscles communicate with the brain and other organs both electrically, via electrical signals sent by the nervous system, and chemically, through the release of neurotransmitters like acetylcholine at the neuromuscular junction.
Step-by-step explanation:
When muscles work, they communicate with the brain, liver, and other organs primarily through chemical and electrical means. Muscles require a stimulus from nerve cells, or motor neurons, which send electrical messages to the muscle fibers to instruct them to contract. This process begins in the brain and involves the nervous system. An action potential, which is an electrical signal, is transmitted along a motor neuron to a muscle at a site called the neuromuscular junction. Here, the neurotransmitter acetylcholine is released, diffuses across the synaptic cleft, and binds to receptors on the muscle fiber, leading to muscle contraction.
Therefore, the communication described in the question is electrical when it involves the nervous system and action potentials, and also chemical when neurotransmitters like acetylcholine are involved at the neuromuscular junction. Thus, the correct answer to the student's question would be a) Chemically and b) Electrically.