marked by hormonal changes that produce secondary sexual characteristics. (2) These include breast development in females and beard growth in males. (3) Psychologically, however, adolescence is a concept that applies only to modern industrial societies. (4) In fact, in most preliterate or tribal societies, the modern American idea of adolescence simply does not exist. (5) In such societies, the social roles of adulthood are to be learned during childhood. (6) Then, around the time of biological puberty, a child becomes an adult through a ritual anthropologists call a rite of passage. (7) By contrast, in American society, adolescence amounts to a sort of social and cultural limbo. (8) Informally, the end of childhood is often marked by one's thirteenth birthday. The child is now a "teenager." (9) More formally, the end of adolescence is marked by legal strictures that vary irrationally. (10) In a given state the age of sexual consent may be 16 for girls and 18 for boys. (11) An 18-year-old may vote or enlist to die for his country, but, until he reaches age 21, he may not legally purchase alcoholic beverages. In which sentence of the paragraph do you find a transitional word or phrase that shows a time connection? A. Sentence 3 B. Sentence 7 C. Sentence 4 D. Sentence 6