Correct Answer: A

Rationale: The correct answer is A: 'Produced outside the body.' In the given sentence, 'exogenous' is used to refer to factors that originate externally, such as environmental influences. Choice B, 'Produced within the body,' is incorrect as it describes endogenous factors. Choice C, 'Produced by the kidneys,' is incorrect as it specifies a specific organ rather than the general concept of external origin. Choice D, 'Hereditary,' is incorrect as it relates to genetic inheritance, which is not the meaning of 'exogenous.'

Correct Answer: C

Rationale: The correct answer is C: 'cause it to happen.' 'Implement' means to put something into action or cause it to happen. Choices A, B, and D are incorrect because they do not reflect the meaning of 'implement.' Preventing something from occurring (Choice A), emphasizing the importance of something (Choice B), and following something from beginning to end (Choice D) are all different actions or concepts that do not align with the definition of 'implement.'

Correct Answer: C

Rationale: The correct answer is 'Were raised.' This phrase is the correct passive form, indicating the action of lifting the glasses during the toast. Choices A, B, and D are incorrect because 'were risen' is not grammatically correct, 'were rose' is not the appropriate verb form, and 'arose' does not convey the action of lifting the glasses as required in the sentence.

Correct Answer: D

Rationale: 'PRN' is a medical abbreviation that stands for 'pro re nata,' meaning 'as needed.' In this context, the medication is given to reduce symptoms as they arise. Choice A, 'Pinpoint,' does not align with the meaning of 'PRN.' Choices B and C, 'Relocate' and 'Eradicate,' are unrelated to the concept of 'as needed' medications.

Correct Answer: A

Rationale: The correct answer is A: 'Is.' In this sentence, 'Economics' is being treated as a singular subject, so the verb should also be singular. 'Is' is the correct singular form of the verb to agree with the singular subject 'Economics.' Choice B, 'Been,' is incorrect because it is the past participle form of the verb 'be' and does not agree with the singular subject 'Economics.' Choice C, 'Am,' is incorrect because it is the first-person singular form of the verb 'be' and does not agree with the singular subject 'Economics.' Choice D, 'Are,' is incorrect because it is the plural form of the verb 'be' and does not agree with the singular subject 'Economics.'