According to the passage, great fear can be stimulated in a child when the story is ______.

A．Father and daughter.
B．Mother and son.
C．Teacher and pupil.
D．Doctor and patient.

A．Fifty percent higher than that of the non-students of the same age.
B．One - quarter of that of the non-students of the same age.
C．Half million.
D．Less than that in the past.