Mark the letter A, B, C or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions from 43 to 44.
Many parents may fail to recognize and respond to their children's needs until frustration explodes into difficult or uncooperative behaviour.
A. stays under pressure
B. remains at an unchanged level
C. suddenly becomes uncontrollable
D. slowly reaches the boiling point