Usually, the baby's eyes will open around 26-28 weeks gestation.
The heart develops around week five, and begins to beat at the end of the 5th week. A heartbeat via ultrasound by 6 weeks, by 10-12 weeks you should hear the heartbeat with a Doppler device. A heartbeat usually won't be detected at 4-5 weeks of pregnancy.
Preparation for childbirth begins anywhere from 30-32 weeks during the process called lightening (the baby turns to a head-down position), however, the baby can flip to the head-down position, then flip again, and so on.
The formation of hair and eyelashes begins during week 22, so the answer is B. Formation of hair and eyelashes.