Complete abortion is characterized by:

Correct Answer: A

Rationale: Complete abortion is characterized by a firm contracted uterus with a closed os. This closure of the os indicates that the products of conception have been completely expelled from the uterus. Choices B, C, and D are incorrect because a firm contracted uterus with a closed os is the hallmark sign of a complete abortion, not heavy bleeding, heavy cramping, or any other features.

Correct Answer: C

Rationale: Tubal abortion is most common when the ovum implants in the interstitial portion of the fallopian tube. This location is the narrowest part of the tube, making it more prone to obstruction or difficulty in the passage of the fertilized ovum. Choices A, B, and D are incorrect because tubal abortion is more likely to occur in the interstitial portion rather than the ampullary portion, isthmus, or infundibulum of the fallopian tube.

Correct Answer: B

Rationale: The correct answer is B: Cardinal ligament. The cardinal ligament is a primary uterine support structure that helps to anchor the uterus in place. The suspensory ligament also provides support for the uterus but is not considered a subsidiary uterine support. The transcervical ligament does not exist in anatomical terminology. The Maklouf ligament is a fictitious term and not recognized as a subsidiary uterine support structure.

Correct Answer: D

Rationale: The lower border is used to differentiate between an abdominal mass and a pelvic mass during clinical examination. The lower border of the mass provides important information about its location and origin. The size (Choice A) alone may not always clearly distinguish between abdominal and pelvic masses. The site (Choice B) and margins (Choice C) are also important factors, but they are not as specific in differentiating between abdominal and pelvic masses as the lower border.

Correct Answer: A

Rationale: The correct answer is A: Mons veneris. The mons veneris and labia majora are considered external genitalia as they are visible externally. The vagina and cervix, on the other hand, are internal structures. The vagina is the canal leading from the external genitals to the cervix, which is the lower, narrow portion of the uterus.