In Humans, Clear Gender Differentiation Occurs Not at Fertilisation, but After

Multiple Choice

In humans, clear gender differentiation occurs not at fertilisation, but after the second month of gestation. Which of the following statements describes the first event of this differentiation?

A) Formation of testosterone in male embryos.
B) Formation of oestrogens in female embryos.
C) Activation of SRY in male embryos and masculinisation of the gonads.
D) Activation of SRY in females and feminisation of the gonads.