Correct Answer: C

Rationale: The correct answer is C. The development of arms and legs occurs during the critical period of the fourth to eighth weeks of pregnancy. This timeframe is crucial for the formation of limbs and other key body parts. Choices A, B, and D are incorrect because the development of the lungs, heart, and stomach respectively occurs at different stages of fetal development and is not primarily associated with the fourth to eighth weeks of pregnancy.

Correct Answer: B

Rationale: The correct interpretation of the assessment provided is that the cervix is dilated 3 cm and effaced 30%; the presenting part is 2 cm above the ischial spines. In the given assessment, the measurements are ordered as dilation, effacement, and station. Choice A is incorrect as it wrongly places the presenting part below the ischial spines. Choice C is incorrect because it places the presenting part below the ischial spines. Choice D is also incorrect as it incorrectly states that the presenting part is below the ischial spines, even though it correctly mentions the dilation and effacement of the cervix.

Correct Answer: A

Rationale: Before meiosis, a sperm cell contains 46 chromosomes. This is because sperm cells, like other somatic cells, have a diploid number of chromosomes. During meiosis, the number of chromosomes is halved to 23 to combine with an egg cell during fertilization. Choice B is incorrect because a sperm cell carries either an X or a Y chromosome, not both (Choice D). Choice C is incorrect as sperm cells are generally smaller than egg cells, which is an adaptation that aids in motility and penetration of the egg during fertilization.

Correct Answer: D

Rationale: The correct answer is D. False labor contractions, also known as Braxton Hicks contractions, are typically irregular and do not lead to cervical dilation or effacement. They are often described as sporadic and temporary, becoming temporarily regular. Choices A, B, and C are incorrect because false labor contractions do not intensify with activity, do not cause cervical changes like dilation and effacement, and are not associated with the presence of a bloody show.

Correct Answer: C

Rationale: Uterine atony is the most likely cause of bleeding 4 hours after delivery, especially after delivering a macrosomic infant and augmenting labor with oxytocin. Uterine atony is characterized by the inability of the uterine muscles to contract effectively after childbirth, leading to excessive bleeding. The other options, such as retained placental fragments (A), unrepaired vaginal lacerations (B), and puerperal infection (D), are less likely causes of postpartum hemorrhage in this scenario. Retained placental fragments can cause bleeding, but this typically presents earlier than 4 hours postpartum. Unrepaired vaginal lacerations would likely be evident sooner and not typically result in significant bleeding. Puerperal infection is not a common cause of immediate postpartum hemorrhage unless there are other signs of infection present.