**Core Concept**
The onset of puberty in females is a complex process involving the coordinated action of various hormonal and physiological changes. It is characterized by the activation of the hypothalamic-pituitary-gonadal (HPG) axis, which regulates the development of secondary sexual characteristics. In females, the first sign of puberty is often a reflection of the initial changes in growth hormone and insulin-like growth factor-1 (IGF-1) levels.

**Why the Correct Answer is Right**
Growth spurt, also known as pubertal growth, is the first noticeable change in females during puberty. This occurs due to the increased production of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) by the pituitary gland and liver, respectively. The growth hormone stimulates the growth of bones, cartilage, and muscles, leading to an overall increase in height and weight. This growth spurt typically begins around 2-3 years before menarche (the onset of menstruation).

**Why Each Wrong Option is Incorrect**
**Option A:** Thelarche, which is the development of breast tissue, usually follows the growth spurt by several months to a year. It is not the first sign of puberty in females.
**Option B:** Menses, or menarche, is the onset of menstrual bleeding and typically occurs around 1-2 years after the growth spurt. It is not the first sign of puberty.
**Option C:** Adrenarche, which is the increase in adrenal androgen production, leads to the development of pubic and axillary hair. While it is an early sign of puberty, it usually occurs after the growth spurt.

**Clinical Pearl / High-Yield Fact**
The growth spurt in females is a critical period for bone growth and development. Adequate nutrition, particularly calcium and vitamin D, is essential to support bone health during this period.

**✓ Correct Answer: D. Growth spu**