As used in the text (Para. 6) the word "petty" most probably means

A．parents drill their children too much in arithmetic
B．principals have explained the new art programs to parents
C．a father can have his son help him construct articles at home
D．parents' misguided efforts can be properly directed

A．home training is more important than school training in that a child spends se many hours with parents
B．teachers can and should help parents to understand the objectives of the school
C．parents need to realize how to cooperate with the teachers in educating their children
D．parents have unconsciously hindered and obstructed curricular objectives