The knee-jerk reflex used by physicians to check nerve response is based on

The knee-jerk reflex used by physicians to check
  nerve response is based on
  a. muscle spindles.
  b. stretch receptors.
  c. spinal cord synapses.
  d. muscle spindles and stretch receptors.
  e. all of these.

Question 2

Which of the following is NOT an example of
  sensory adaptation?
  a. a loss of the sense of pressure of clothes against
  the skin
  b. adjustment to repeated jumping into a body of
  cold water
  c. response to lack of oxygen at high altitudes
  d. eventual loss of awareness of a constant noise
  e. the loss of the ability to smell a persons
  perfume after being in that persons presence for
  some time