In the following question, out of the four alternatives, select the word which is most similar in meaning to the given word: Cluster.

Introduction / Context:
This vocabulary question asks for a synonym, that is, a word with a similar meaning, for the word "cluster". Such questions test your knowledge of word meanings and your ability to recognise related ideas in different lexical forms. "Cluster" is frequently used in everyday English as well as in academic contexts, so knowing its sense and common collocations is useful for reading comprehension and verbal ability sections of competitive exams.

Given Data / Assumptions:

• The target word is "cluster".
• The options are "Individual", "Assemblage", "Specific", "Solitary", and "Unit".
• No sentence context is provided, so we rely on the core dictionary meaning of "cluster".
• We assume the exam expects the most common general meaning.
• "Cluster" can refer to a group of similar things close together in space or time.

Concept / Approach:
In its basic noun sense, "cluster" means a group of similar things or people positioned or occurring closely together. Examples include a cluster of stars, a cluster of houses, or a cluster of grapes. Therefore, we should look for an option that also refers to a group or collection rather than a single item. Among the options, "Assemblage" almost directly captures this idea: it means a collection or gathering of things or people. Other options point to singularity or other concepts and therefore do not match the sense of "cluster".

Step-by-Step Solution:
Step 1: Recall the meaning of "cluster" as a noun: a group or bunch of similar items. Step 2: Examine "Assemblage". It means a collection or gathering of things or people. This clearly aligns with the idea of a group. Step 3: Examine "Individual". This refers to a single person or thing, which is the opposite of a group. Step 4: Examine "Specific". This relates to being clearly defined or identified and does not express the idea of grouping. Step 5: Examine "Solitary". This again emphasises being alone, not in a group, which is opposite to "cluster". Step 6: Examine "Unit". While a unit can be part of a group, the word itself implies a single entity, not a collection. Step 7: Conclude that "Assemblage" is the only option that directly carries the sense of a group of items or people.

Verification / Alternative check:
We can confirm the choice by substituting in example phrases. "A cluster of stars" could be described as "an assemblage of stars". "A cluster of small cottages" could be "an assemblage of small cottages", both expressing a group. In contrast, replacing "cluster" with "individual" or "solitary" would completely change the meaning to a single item, showing that these are not synonyms. This cross-checking with context confirms that "Assemblage" is the closest synonym among the options.

Why Other Options Are Wrong:
"Individual" focuses on a single person or thing, which is the opposite of a group and therefore cannot be a synonym of "cluster". "Specific" describes something that is clearly defined or particular in nature; it says nothing about whether there is one or many items. "Solitary" emphasises being alone, without companions, which clashes directly with the group meaning of "cluster". "Unit" refers to one thing that may belong to a group, but the word itself highlights the single component rather than the collection.

Common Pitfalls:
A common mistake is to choose a word that seems vaguely formal or unusual, assuming it must be the synonym. Another pitfall is to pick a word that can appear in similar contexts without checking whether it actually shares the same core meaning. Always try to recall or construct at least one clear sentence using the target word, and see which option can replace it without changing the overall sense of the sentence.

Final Answer:
The word most similar in meaning to "cluster" is Assemblage.