Correct Answer: C

Rationale: Thalidomide is the correct answer. Thalidomide was a drug marketed in the 1960s to pregnant women as a sedative and anti-nausea medication but tragically led to severe birth defects, including limb deformities, when taken during pregnancy. Progestin (Choice A) and Estrogen (Choice B) are hormones that are not associated with causing birth defects like Thalidomide. Oxytocin (Choice D) is a hormone that plays a role in labor and breastfeeding and is not known to cause birth defects like Thalidomide.

Correct Answer: D

Rationale: Rh incompatibility occurs when the mother's antibodies attack the fetus's red blood cells, leading to serious complications, usually in subsequent pregnancies. Choice A is incorrect because Rh incompatibility often occurs in subsequent pregnancies, not necessarily the first one. Choice B is incorrect as Rh incompatibility does not render a woman infertile but can lead to complications during pregnancies. Choice C is incorrect as Rh incompatibility is not carried by a sex chromosome but involves the Rh factor on red blood cells.

Correct Answer: C

Rationale: The correct answer is 'Motility.' Motility refers to the ability of cells or organisms to move by themselves, often through the use of specialized structures like flagella or cilia. Mitosis (Choice A) and Meiosis (Choice B) are processes related to cell division and genetic recombination, respectively, not self-propulsion. Mutation (Choice D) refers to changes in the DNA sequence and is not related to self-propulsion.

Correct Answer: C

Rationale: Down's syndrome, also known as trisomy 21, is caused by the presence of an extra chromosome on the 21st pair. Choice A is incorrect as alcohol abuse is not the cause of Down's syndrome. Choice B is incorrect because Down's syndrome is not related to sex-linked chromosomal abnormalities. Choice D is also incorrect as drug abuse by the mother during pregnancy is not the cause of Down's syndrome.

Correct Answer: C

Rationale: Initiating seizure precautions is crucial when caring for an infant with neonatal abstinence syndrome due to the increased risk of seizures. Providing a calm environment (Choice A) is important to reduce stimulation as these infants may be irritable. Monitoring blood glucose levels (Choice B) is not typically a priority in neonatal abstinence syndrome unless specific signs or symptoms suggest the need for this assessment. Placing the infant on their back with legs extended (Choice D) does not directly address the potential complications associated with neonatal abstinence syndrome, such as seizures.