What does the word “that” in paragraph 2 refer to?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 31- 35

In most families, conflict is more likely to be about clothing, music, and leisure time than about more serious matters such as religion and core values. Family conflict is rarely about such major issues as adolescents' drug use and delinquency. Nevertheless, it has been estimated that in about 5 million American families (roughly 20 percent), parents and adolescents engage in intense, prolonged, unhealthy conflict. In its most serious form, this highly stressful environment is associated with a number of negative outcomes, including juvenile delinquency, moving away from home, increased school dropout rates, unplanned pregnancy, membership in religious cults, and drug abuse (Steinberg & Morris, 2001).

Many of the changes that define adolescence can lead to conflict in parent- adolescent relationships. Adolescents gain an increased capacity for logical reasoning, which leads them to demand reasons for things they previously accepted without question, and the chance to argue the other side (Maccoby,1984). Their growing critical-thinking skills make them less likely to conform to parents' wishes the way they did in childhood. Their increasing cognitive sophistication and sense of idealism may compel them to point out logical flaws and inconsistencies in parents' positions and actions. Adolescents no longer accept their parents as unquestioned authorities. They recognize that other opinions also have merit and they are learning how to form and state their own opinions. Adolescents also tend toward ego-centrism, and may, as a result, be ultra-sensitive to a parent's casual remark. The dramatic changes of puberty and adolescence may make it difficult for parents to rely on their children's preadolescent behavior to predict future behavior. For example, adolescent children who were compliant in the past may become less willing to cooperate without what they feel is a satisfactory explanation.

What is the passage mainly about?