What physical change occurs at Tanner stage II for females?

At Tanner stage II for females, the development of a breast bud is the prominent physical change that occurs. This stage marks the beginning of breast development, where small lumps or elevations form under the nipple as the mammary glands start to grow. This budding is typically one of the first visible signs of puberty, representing the body's preparation for future reproductive capability.

Breast development progresses through several stages, and Tanner stage II is characterized specifically by this initial formation. The other options either represent later stages of development or other changes that occur at different points in puberty. For instance, the adult breast size is reached much later in the Tanner stages, and the first menstrual cycle, or menarche, usually occurs during Tanner stage III or IV. Additionally, the areola's contour change occurs after the breast bud is established, solidifying why the formation of the breast bud is the correct choice for Tanner stage II.