$A$ person entering an empty room suddenly finds a snake right in front on opening the door. Which one of the following is likely to happen in his neuro-hormonal control system?

• A
  Sympathetic nervous system is activated releasing epinephrine and norepinephrine from adrenal medulla.
• B
  Neurotransmitters diffuse rapidly across the cleft and transmit a nerve impulse.
• C
  Hypothalamus activates the parasympathetic division of brain.
• D
  Sympathetic nervous system is activated releasing epinephrine and norepinephrine from adrenal cortex.