Which happens during the second trimester?

O A. The vocal cords develop.

O B. The heart starts working.

C. Rhythmic breathing starts.

D. Blood begins to form.

The baby's organs become fully developed during the second trimester. The baby can also start to hear and swallow. Small hairs become noticeable. Later on in the second trimester, the baby will begin to move around. It will develop sleeping and waking cycles that a pregnant woman will begin to notice. I would know which one above to choose but that's what happens