Recently, researchers analyzed the neural circuits of experimental rats and found the pathogenic genes that cause idiopathic tremors. The researchers analyzed the genes of the experimental rats with strong tremors in the lower body and their central nervous system when walking. The "mTeneuxirr-4" gene has been mutated, causing no myelin to form outside the axons of nerve cells. Nerves are similar to wires, axons are equivalent to wires in wires, and the myelin sheath is like an insulating layer covering the wires. It was because the myelin sheath did not form properly that the neural circuit was "short-circuited", and the shock symptoms appeared. Based on this, the researchers concluded that the reason for this shock in humans is the same. For a researcher's argument to be valid, which of the following prerequisites need to be added most? ['The study found that myelin hypoplasia also exists in transgenic experimental mice whose gene function is inhibited by "Teneurirr-4".', 'Humans have the same "Teneuxirr-4" gene.', 'c. Idiopathic tremor has been thought to be caused by genes, but the specific genes associated with it and the detailed mechanisms that cause symptoms have not been known before.', 'Humans with idiopathic tremor have the same symptoms as laboratory rats.']