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: B

Rationale: The correct answer is 'Fontanel.' Fontanels are the soft spots on a newborn's head where the skull bones have not yet fused together, allowing for some flexibility during birth and rapid brain growth in early infancy. 'Fistula' is a medical term for an abnormal connection between two body parts. 'Follicle' refers to a small cavity in the skin from which hair grows. 'Fissure' is a narrow opening or crack, not related to the soft spots on a newborn's head.

Correct Answer: B

Rationale: 'Biologists' is a noun in the sentence, referring to a group of people who study wildlife and their behaviors. In this context, 'biologists' is not describing or modifying another noun, making it a noun itself. Therefore, options A, C, and D are incorrect.

Correct Answer: A

Rationale: The correct answer is A: 'Plethora.' In the context provided, 'cornucopia' is used metaphorically to signify an abundance or a large variety of stimulating questions and conversation. 'Plethora' is a synonym for 'cornucopia' and means an excessive amount or abundance. Choices B, C, and D are incorrect. 'Ostracism' means exclusion or rejection, 'Laborious' means requiring a lot of effort, and 'Pensive' means engaged in deep thought.

Correct Answer: C

Rationale: The correct answer is C: 'Easiest.' The word 'easiest' is the correct superlative form of 'easy,' which is used to compare one item against others in terms of degree. 'Most easiest' and 'most easy' are grammatically incorrect. Choice D, 'Easy,' is incorrect as it is not a superlative form and does not convey a comparison of the test against others in the course.