The physician determines that Ashley is in her twentieth week of pregnancy. Which of the following best describes the development of the fetus at this time (refer to table 29.3)?

The physician determines that Ashley is in her twentieth week of pregnancy. Which of the following best describes the development of the fetus at this time (refer to table 29.3)? a. The crown–rump length is 19 centimeters. b. The heart and lungs have fully developed, but the GI tract has yet to form. c. The testes have descended into the scrotum. d. The average weight of the fetus at this time is about 2.5 kilograms. Transcribed Image Text: Table 29.3
Fetal Stage of Development
Time Period
Major Events
Primary ossification centers appear in most bones
Reproductive organs begin to develop
Wooks 9-12
Coordination between nerves and muscles for movement of limbs occurs
Brain enlarges
Body elongates
Epidermis and dermis of the skin become more fully devekoped
Permanent kidneys develop
Palate (roof of mouth) develops
CRL: 9 cm
Average head circumference at 12 weeks: 68 millimeters (mm)
Average crown-rump length at 12 weeks: 9 centimeters (em)
Average weight: 28 grams (g)
Woeks 13-16
Body grows rapidly
Ossification in the skeleton continues
Limbs become more propartionate in length to body
Brain and skull eontinue to enlarge
Average head circumference at 16 weeks: 123 mm (12.3 cm)
Average crown unp length at 16 weeks 14 em
Average weight: 170g
CRL: 14 cm
Wooks 17-2O
Muscle movements become stronger and more frequent
Lanugo covers skin
Vernix caseosa covers skin
Limhs near final proportions
Brain and skull contimue to enlarge
Average head circumference at 20 weeks: 174.5 mm (17.45 cm)
Average crown-rump length at 20 weeks: 19 cm
Average weight: 454 g
CRL: 19 cm
Wooks 21-38
Body gains major amount of weight
Subcutancous fat is deposited
Eyebrown and eyelashes appear
Eyelids open
Testes descend into scrotum (month 9)
Blood cells form in marrow only
Average head circumference at 38 wocks: 335 mm (33.5 cm)
Average crown-rump length at 38 weeks 36 cm
Average tolal length at 38 weeks: 53 cm
Average weight: 2.5-4.5 kilograms (kg)
CHL: 36 cm