The correct option is C Sixth
The heart of the foetus develops after one month of pregnancy.
By the end of second month, limbs and digits develop.
By the end of the first trimester, all the major organs are formed.
By the fifth month, the foetus starts to move around and hair appears on its head.
By the end of the second trimester, body is covered with fine hair, the eye lids separate and eye lashes are formed.
By the end of 9 months, the foetus is fully developed and ready to be delivered.