Correct Answer: B

Rationale: A mass of tissue formed in the ovary is known as the corpus luteum. The corpus luteum is a temporary endocrine structure involved in the production of progesterone, which is essential for preparing and maintaining the uterus for pregnancy. Choices A, C, and D are incorrect. Corpus delicti refers to the body of a crime, corpus striatum is a part of the brain, and corpus callosum is a structure that connects the two hemispheres of the brain.

Correct Answer: C

Rationale: In the context of the sentence, the word 'placebo' refers to a substance or treatment that resembles a real medical treatment but has no therapeutic effect. It is used as a standard against which the effects of the experimental drug are compared. A placebo is typically included in a control group in medical research to evaluate the actual effects of the experimental drug. Therefore, in this scenario, the placebo serves as a control to gauge the effectiveness of the experimental drug, making choice C the correct answer. Choices A, B, and D are incorrect because a placebo is not a fallback, substitute, or curative treatment in this context.

Correct Answer: B

Rationale: The correct answer is B: Caesarean. The C in C-section stands for 'Caesarean' after Julius Caesar, who was rumored to have been born via this surgical procedure. The term 'Caesarean' is derived from the Latin word 'caesus,' meaning cut or incised. Choice A, Carthusian, is incorrect as it does not relate to childbirth. Choice C, Cartesian, is unrelated to the medical procedure. Choice D, Caedmon, is also irrelevant in the context of C-sections.

Correct Answer: B

Rationale: The word 'ameliorate' means to improve or make something better. In this sentence, the question is asking whether the dosage made the tenderness better, indicating an improvement in the condition. Therefore, the correct meaning of 'ameliorate' is to improve, making option B the correct choice. Choices A, C, and D are incorrect as they do not accurately reflect the meaning of 'ameliorate' in the context provided.

Correct Answer: B

Rationale: The word 'sanguinary' is derived from the Latin word 'sanguinarius,' meaning bloodthirsty or bloodshed. In the context of the sentence, 'sanguinary' is used to indicate that surgery is a procedure that involves bloodshed. Therefore, the correct answer is B. Choice A ('Hopeful or cheerful') is incorrect because 'sanguinary' does not convey a positive or cheerful meaning. Choice C ('Difficult and protracted') is incorrect as 'sanguinary' specifically relates to blood or bloodshed, not difficulty or prolongation. Choice D ('Tricky and sensitive') is incorrect as 'sanguinary' does not imply trickiness or sensitivity but rather the presence of blood or bloodshed.