Correct Answer: A

Rationale: The correct answer is 'Chronology,' which specifically means the arrangement of events in the order of their occurrence. 'Notation' refers to a system of symbols or signs used to represent information. 'Documentation' is the process of recording information, while 'Helicon' does not relate to the description of events.

Correct Answer: A

Rationale: The correct usage of 'etc.' should follow a comma when concluding a list. Option A correctly places 'etc.' at the end of a logical list with a comma before it, following grammatical rules. In option B, a comma should be placed after 'etc.' before introducing 'and other items.' Options C and D either misplace commas or incorrectly use 'etc.' within the list.

Correct Answer: D

Rationale: The correct answer is 'Ventral' because it specifically refers to the lower surface of a structure. 'Inferior' means below in position, 'Transverse' means situated across something, and 'Dorsal' refers to the upper side or back of a structure, making them incorrect in the context of the lower surface of a structure.

Correct Answer: A

Rationale: The correct answer is 'Regimen.' 'Regimen' refers to a prescribed set of procedures or a routine, especially related to health. Choice B, 'Regime,' typically refers to a system of government or a ruling period. Choice C, 'Testament,' means a person's will or a statement of belief. Choice D, 'Treatment,' is a medical care given to a patient.

Correct Answer: C

Rationale: The correct answer is C: 'Gradual.' In the context provided, 'insidious' describes a disease that develops slowly and harmfully over time, without being easily noticed. Choices A, B, and D are incorrect. 'Sudden' (choice A) means something happening quickly or unexpectedly, 'Suffer' (choice B) means to experience pain or hardship, and 'Graduate' (choice D) means to successfully complete a process or course of study, none of which capture the intended meaning of 'insidious' in this context.