Answer:

Introduction:
This question belongs to the Logical Reasoning (LR) category and tests the understanding of the word 'Bargain' and its association with a specific concept or idea. The task is to identify the option that is always associated with 'Bargain' among the given choices: (a) Exchange, (b) Sumptuousness, (c) Triviality, and (d) Eloquence.

Understanding the Term 'Bargain':
- A bargain generally refers to a transaction or agreement where two parties come to terms on a specific issue, usually involving a financial exchange.
- It implies a negotiation or deal between parties to reach a mutually beneficial outcome.
- The concept of a bargain is commonly associated with getting a good deal or value for one's money.

Options Analysis:
a) Exchange:
- The term 'exchange' is closely related to the concept of a bargain.
- In a bargain, there is often an exchange of goods, services, or money between the parties involved.
- This option is aligned with the definition and understanding of a bargain, making it a suitable answer choice.

b) Sumptuousness:
- Sumptuousness refers to luxuriousness or extravagance.
- This term does not necessarily connect with the concept of a bargain, as a bargain implies a good deal or value, often involving cost savings.
- Thus, sumptuousness is not always associated with a bargain.

c) Triviality:
- Triviality refers to something unimportant or insignificant.
- A bargain, on the other hand, involves a significant negotiation or agreement that has value or importance to the parties involved.
- Triviality is not inherently linked to a bargain, making it an incorrect answer choice.

d) Eloquence:
- Eloquence refers to the ability to speak or write fluently and persuasively.
- While effective communication skills might be useful in negotiating a bargain, eloquence itself is not an essential component of a bargain.
- Eloquence does not consistently accompany the concept of a bargain.

Conclusion:
After analyzing the given options, it is evident that the term 'Exchange' is the most appropriate choice that is always associated with the word 'Bargain.' The concept of exchange aligns closely with the definition and understanding of a bargain as a negotiation or deal involving the exchange of goods, services, or money.