A 5-year-old girl is brought to the clinic because she has started developing breast tissue and pubic hair. The parents report a recent growth spurt. Which of the following conditions is most likely?

A. Delayed puberty is incorrect because delayed puberty refers to absence or incomplete development of secondary sexual characteristics beyond the expected age (usually after age 13 in girls). This child is showing early development, not delayed development. B. Hypothyroidism is incorrect because hypothyroidism in children typically causes growth retardation, delayed bone age, fatigue, and weight gain, rather than early sexual maturation. It does not explain the growth spurt and development of secondary sexual characteristics. C. Precocious puberty is correct because it is defined as the onset of secondary sexual characteristics before age 8 in girls. The child’s early breast development, pubic hair, and accelerated growth are classic signs of precocious puberty. This condition may be central (GnRH-dependent) or peripheral (GnRH-independent) and warrants further endocrine evaluation. D. Hyperthyroidism is incorrect because while hyperthyroidism can cause accelerated growth and early bone maturation, it does not typically trigger premature development of secondary sexual characteristics.