Which of the following statements describes the functio...
单项选择题Which of the following statements describes the function of the myelin sheath?()
A．To increase energy required for ion pumps.
B．To allow impulses to transmit rapidly and efficiently along the nerve cells.
C．To sustain the survival of the nerve cells.
D．To give rigidity to the axons so that they can project farther.
E．To provide physical protection to the axons.
