To be diagnosed with childhood onset conduct disorder,which of the following must be true

A-At least three symptoms must be present prior to 8 years of age
B-At least three symptoms must be present prior to 10 years of age
C-No symptoms must be present after 10 years of age
D-At least one symptom must be present prior to 10 years of age

B- At least three symptoms must be present prior to 10 years of age.