In the following question, out of the four alternatives, select the alternative which is the best one-word substitute for the given phrase: "things that have been discarded as worthless."

Introduction / Context:
This vocabulary question tests knowledge of specific English nouns that describe waste, wreckage or disorder. The phrase given is "things that have been discarded as worthless." You must choose the single word that best captures this meaning in a concise way, paying attention both to dictionary definitions and to typical usage in context.

Given Data / Assumptions:

• Target phrase: things that have been discarded as worthless.
• Option A: remains.
• Option B: flotsam.
• Option C: shambles.
• Option D: havoc.
• We assume standard modern English usage and that the exam is testing common but slightly advanced vocabulary.

Concept / Approach:
The word "flotsam" originally referred to debris or wreckage found floating on the sea after a shipwreck, but it is also used figuratively to mean bits and pieces of things that are considered worthless or discarded. In contrast, "remains" usually refers to leftover parts of something (often neutral) or human remains, "shambles" describes a state of great disorder or mess, and "havoc" means widespread destruction or chaos. Among these, only "flotsam" directly focuses on discarded, valueless items.

Step-by-Step Solution:
Step 1: Focus on the crucial idea in the phrase: items that have been thrown away because they are seen as worthless, not merely disordered or left over.Step 2: Examine "remains". This can mean what is left after the main part is taken, or it can refer to a dead body. It does not necessarily imply worthlessness or deliberate discarding, so it is too general.Step 3: Examine "flotsam". Traditionally, flotsam is floating wreckage after a ship disaster. In everyday language, it is also used metaphorically for fragments, odds and ends or junk that people have discarded.Step 4: Examine "shambles". This word refers to a place or situation that is in total disorder or ruin, such as "The room was a shambles." It describes a messy state, not specifically discarded objects.Step 5: Examine "havoc". "Havoc" is chaos, confusion or widespread damage. It does not refer to the physical discarded things but to the destructive effect itself. Therefore, "flotsam" comes closest to "discarded worthless things".

Verification / Alternative check:
Consider example sentences. "The beach was littered with plastic flotsam" clearly refers to scattered, unwanted debris. You can also read about "the flotsam and jetsam of city life", meaning people and possessions that seem discarded or unwanted. Using "remains" in those sentences would lose the sense of worthlessness, and "shambles" or "havoc" would change the meaning to "mess" or "destruction", not to things thrown away.

Why Other Options Are Wrong:
Option A, "remains", is too broad and often used in serious contexts like "human remains", not specifically "worthless junk". Option C, "shambles", talks about disorder rather than the items causing it. Option D, "havoc", focuses on destruction and chaos rather than the material objects that result from it. None of these words alone means "things that have been discarded as worthless".

Common Pitfalls:
Students may associate "shambles" and "havoc" with messy or broken situations and think they are close to garbage. However, the question asks specifically for "things" that have been discarded, not the chaos itself. It is important to distinguish between words that describe states (chaos, disorder) and those that label physical objects (wreckage, junk). "Flotsam" fits the latter category.

Final Answer:
The best one-word substitute for "things that have been discarded as worthless" is flotsam, so option B is correct.