20. Choose the meaning that best fits the quoted word. The doctor tried to explain the 'fundamental' difference of the two medications.

Answer: D

Explanation:

Basic

The word 'fundamental' in this context refers to something that is essential or basic to the understanding of the difference between the two medications. Thus, 'basic' is the most fitting synonym for 'fundamental' in this scenario.

A) Appropriate

While 'appropriate' suggests something that is suitable or proper in a given situation, it does not capture the essence of 'fundamental.' The difference being discussed is not about suitability but rather about essential characteristics, making this option incorrect.

B) Underlying

'Underlying' refers to something that is the basis or cause of something else. Although it might seem relevant, it does not convey the same idea as 'fundamental.' The focus here is on the basic distinctions rather than causes or foundations, leading to this option being incorrect.

C) Dosage

'Dosage' specifically relates to the amount or frequency of medication administered, which is not relevant to the concept of 'fundamental.' The term does not relate to differences in characteristics or nature and is therefore not applicable in this context.

D) Basic

'Basic' accurately captures the meaning of 'fundamental' as it pertains to the essential and primary aspects of the differences between the two medications. This makes it the correct choice, as it aligns perfectly with the intended meaning.

Conclusion

In summary, 'basic' is the most appropriate synonym for 'fundamental' as it conveys the core idea of essential differences. All other options fail to encapsulate this fundamental aspect, focusing instead on suitability, causation, or unrelated concepts. Hence, D is definitively the correct answer.