Correct Answer: B

Rationale: Non-Hispanic White Americans have the lowest incidence of gestational diabetes mellitus (GDM) compared to other ethnicities. This is because GDM is more prevalent among certain ethnic groups, such as Asian, Hispanic, and African American populations. Asian individuals have an increased risk of developing GDM due to genetic factors, while Hispanic and African American populations have higher incidences of GDM due to lifestyle and genetic predispositions. Therefore, the correct answer is B, as Non-Hispanic White Americans generally have a lower risk of developing GDM.

Correct Answer: D

Rationale: The correct answer is D, Rubella. Rubella vaccine is recommended postpartum to prevent congenital rubella syndrome in future pregnancies. Pneumococcal and Hepatitis vaccines are not routinely given postpartum. Human papillomavirus vaccine is not typically administered immediately after birth but rather at a later age to prevent HPV infections.

Correct Answer: C

Rationale: The correct answer is C: 'Breast Tenderness.' Clomiphene citrate is known to cause breast tenderness as a common side effect due to its hormonal effects on the body. Tinnitus (choice A), which is a ringing in the ears, is not typically associated with clomiphene citrate. Urinary frequency (choice B) is not a common adverse effect of this medication. Chills (choice D) are also not commonly linked to clomiphene citrate use.

Correct Answer: A

Rationale: The correct answer is A. Tay-Sachs disease is most commonly found among Jewish families of Eastern European descent. It is a fatal genetic disorder that affects the nervous system. Choice B is incorrect because Tay-Sachs disease does not involve excessive mucus production in the lungs and pancreas. Choice C is incorrect as it states that Tay-Sachs disease is most commonly found among Asian American families, which is inaccurate. Choice D is also incorrect because Tay-Sachs disease does not cause muscular dystrophy characterized by weakening of the muscles.

Correct Answer: A

Rationale: The correct answer is A: codominance. Codominance refers to a genetic scenario where both alleles in a gene pair are fully expressed, leading to a phenotype that displays traits from both alleles equally. This is distinct from incomplete dominance where the traits blend. Choices B, C, and D are incorrect. Preponderance does not specifically relate to the expression of alleles. Ascendance and concurrence do not describe the genetic concept of codominance where both alleles are fully expressed.