During which phase do people experience significant physical growth and sexual maturation?

The correct answer is puberty. This phase is characterized by dramatic physical changes and the development of secondary sexual characteristics, marking the transition from childhood to adolescence. During puberty, both boys and girls experience hormonal changes that lead to growth spurts, the development of reproductive organs, and the onset of menstruation in girls and sperm production in boys. This period is crucial for sexual maturation and sets the stage for the physical and psychological changes associated with becoming an adult.

The other phases mentioned do not encompass the same level of significant physical growth and sexual development. Late adolescence refers to a stage that typically follows puberty and focuses more on social and emotional development rather than the physiological changes that occur during puberty itself. The preoperational stage is a concept from cognitive development theory that relates to early childhood and is not associated with physical growth. Late childhood, while it involves some growth, does not include the marked sexual maturation that defines puberty.