Correct Answer: B

Rationale: The correct answer is B: Lipoma. A lipoma is a common benign tumor made of fat cells. In this case, the patient's presentation of a painless, soft, round, flesh-colored lump with smooth borders is consistent with a lipoma. The absence of symptoms like pain, erythema, or tenderness further supports this diagnosis. Lipomas are usually non-tender to palpation and can grow to a significant size. The other choices (A, C, D) are not the correct answers because they do not align with the characteristics described in the patient's presentation. Neurolemma is associated with nerve sheath tumors, hemangioma with blood vessel tumors, and lymphangioma with lymphatic vessel tumors, none of which match the clinical findings in this case.

Correct Answer: C

Rationale: The correct answer is C because in obstructive shock due to a large pulmonary embolus, there is increased resistance to blood flow out of the right ventricle, leading to elevated right ventricular pressure. This causes a backup of blood into the pulmonary circulation, increasing left ventricular pressure. The increased left ventricular pressure results in decreased cardiac output as the left ventricle struggles to pump against the increased resistance. A: Elevated atrial and decreased ventricular pressures - This is incorrect as obstructive shock typically results in elevated ventricular pressures due to increased resistance. B: Elevated right-sided and decreased left-sided pressures - This is partially true, but C is a more complete answer that explains the consequences of these pressures on cardiac output. D: Elevated left ventricular pressure and decreased systemic vascular resistance - This is incorrect as obstructive shock leads to increased, not decreased, systemic vascular resistance due to the embolus obstructing blood flow.

Correct Answer: B

Rationale: The correct answer is B: Escherichia coli. Puerperal sepsis is often caused by endogenous bacteria from the mother's own flora. E. coli is a common endogenous bacteria found in the gastrointestinal tract and can cause infection during childbirth. Chlamydia trachomatis is a sexually transmitted infection, not typically associated with puerperal sepsis. Clostridium tetani causes tetanus, not puerperal sepsis. Pseudomonas aeruginosa is an environmental pathogen, not typically an endogenous cause of puerperal sepsis.

Correct Answer: A

Rationale: The correct answer is A (36 weeks gestation) because at this point in pregnancy, the fetus has reached a stable lie position. Before 36 weeks, fetal lie can vary due to the ample space in the uterus. After 36 weeks, the fetus tends to settle into a consistent head-down or breech position, making the lie stable. Choices B, C, and D are incorrect as they are past the point where the lie typically stabilizes, leading to less variability in fetal positioning.

Correct Answer: D

Rationale: The correct answer is D. A ruptured uterus can lead to fetal distress and necessitate a cesarean section. Failure of the cervix to dilate is indicative of a potential uterine rupture, as the uterus may not be able to contract effectively due to the rupture. Maternal dehydration (A), pyrexia (B), and oliguria (C) are not specific signs of a ruptured uterus and may be present in various other conditions. Therefore, failure of the cervix to dilate is the most relevant early sign in this scenario.