What is considered the first physical sign of puberty in human females?

At the embryonic stage of human development, the germ layer 'Mesoderm' develops into which of the following?

Select the teratogens and environmental factors that negatively affect prenatal growth from the list given below: (a) Non-prescribed illegal drugs (b) Excessive quantity of caffeine (c) Protein-rich diet (d) Extreme heat and humidity (e) Milk and milk products Choose the most appropriate answer from the options given below: