Which hormone is primarily responsible for sexual changes in females during puberty?

Oestrogen is primarily responsible for the development of sexual characteristics in females during puberty. This hormone plays a critical role in regulating the menstrual cycle, promoting breast development, and facilitating the maturation of the reproductive system. It is produced mainly by the ovaries and contributes to the growth of secondary sexual traits, such as the development of wider hips and the distribution of body fat.

While testosterone is often associated with male puberty, it is also present in females, but its role is less prominent during this stage. Adrenaline and cortisol are hormones related to stress response and metabolism, respectively, and do not directly influence sexual development during puberty. Therefore, the central role of oestrogen in prompting these significant changes during puberty makes it the correct choice.