A class of immunoglobulins found concentrated in breast milk, and thus serve to passively and naturally enhance the specific immune system of a newborn is:

Correct Answer: A

Rationale: IgA in breast milk provides passive mucosal immunity to newborns.

Correct Answer: C

Rationale: Dartos muscle wrinkles scrotum, aiding temperature regulation indirectly.

Correct Answer: A

Rationale: Antacids neutralize gastric acid, providing symptomatic relief and promoting healing, making them a cornerstone of traditional peptic ulcer management.

Correct Answer: C

Rationale: Pyogenic liver abscesses present with a dramatic clinical picture (fever, pain), often multiple, and jaundice is uncommon unless biliary obstruction occurs.

Correct Answer: D

Rationale: All listed cancers "kidney, thyroid, breast, and prostate "frequently metastasize to bone due to their vascular spread patterns.