According to Para.3, which of the following statements is TRUE

A．It is harder to track the precise effects of parental upbringing than the exact influence of the peer group in children.
B．Immigrant children tend to discard the war their parents speak quickly when they go to school.
C．It has been proved that peers have more impact on children's qualifies such as to be honest or hard-working or generous.
D．It is easier for children to acquire a language at school than at home.