Answer: Adolescence is generally considered to begin with the onset of puberty (option A).
Step-by-step explanation:
Adolescence is a transitional period between childhood and adulthood. It is characterized by various physical, cognitive, and emotional changes. One of the key events that marks the beginning of adolescence is puberty.
Puberty is the stage of development during which a person becomes capable of sexual reproduction. It is initiated by hormonal changes that lead to physical changes in the body. These changes include the development of secondary sexual characteristics, such as the growth of breasts in girls and facial hair in boys.
The onset of puberty is determined by the release of hormones, specifically gonadotropin-releasing hormone (GnRH), by the hypothalamus. This hormone stimulates the pituitary gland to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which in turn trigger the production of sex hormones such as estrogen and testosterone.
Therefore, adolescence is generally considered to begin with the onset of puberty, as it signifies the beginning of physical and hormonal changes that are characteristic of this developmental stage.