Read the passage and answer the questions A and B.

Children must pass through several stages in their lives to become adults. For most people, there are  four or five such stages of growth where they learn certain things : infancy (birth to age 2), early  childhood (3 to 8 years), later childhood (9 to 12 years) and adolescence (13 to 18 years). Persons 18  and over are considered adults in our society. Of course, there are some who will try to act older than  their years. But, for the most part, most individuals have to go through these stages irrespective of  their economic or social status. World Health Organisation (WHO) identifies adolescence as the period in human growth and  development that occurs after childhood and before adulthood. This phase represents one of the  critical transitions in one's life span and is characterised by fast-paced growth and change which are  second only to those at infancy. Biological processes drive many aspects of this growth and  development with the onset of puberty marking the passage from childhood to adolescencE- The  biological determinants of adolescence are fairly universal; however, the duration and defining  characteristics of this period may vary across time, cultures, and socio-economic situations. This  period has seen many changes over the past century-puberty, for example, comes earlier than before,  people marry late, and their sexual attitudes and behaviours are different from their grandparents, or  even parents. Among the factors responsible for the change are education, urbanization and spread of  global communication. The time of adolescence is a period of preparation for adulthood during which one experiences several  key developments. Besides physical and sexual maturation, these experiences include movement  toward social and economic independence, development of identity, the acquisition of skills needed to  carry out adult relationships and roles and the capacity for abstract reasoning. While adolescence is a  time of tremendous growth and potential, it is also a time of considerable risks during which social  contexts exert powerful influences. Many adolescents face pressure to use alcohol, cigarettes, or other drugs and to initiate sexual  relationships putting themselves at high risk for intentional and unintentional injuries, unintended  pregnancies, and Sexually Transmitted Infections (STIs), including the Human Immunodeficiency Virus  (HIV). Many also experience a wide range of adjustment and mental health problems.