B I think. Hope it's correct.
Learn about fetal development<span> in the </span>first month<span> of pregnancy. ... </span>During<span> sex, the man's penis releases a thick, whitish fluid called semen into the woman's ... Soon the </span>cells<span> separate into two parts: a thin outer </span>cell layer<span> and an inner </span>cell<span> mass. ... the </span>embryo<span> receives its nourishment and oxygen from ..</span><span>.</span>
