In this verbal analogy question, “Thread is to String as Cask is to ______”. Choose the word that stands to “Cask” in the same way that a string is related to a thread.

Introduction / Context:
This is a classic verbal analogy from aptitude reasoning. The structure is “Thread is to String as Cask is to ?”. In such questions, you must understand the relationship between the first pair of words and then find the option that has the same kind of relationship with the second given word. These analogies test vocabulary, word associations, and the ability to see part–whole or type–class relationships rather than guessing purely by memory.

Given Data / Assumptions:

• First pair: Thread and String. • Second word given: Cask. • Options: Barrel, Disc, Wallet, Box. • We work with standard English meanings used in general aptitude exams. • The relationship in both pairs should be of the same logical type, for example type–class, part–whole, or synonym.

Concept / Approach:
A string is essentially a kind of thin cord made of twisted or interwoven threads. In simple language, a thread is a basic unit and a string is the thicker, more complete form built from threads. So thread and string are closely related; the string is the familiar, larger object and thread is a basic element in that context. For the second pair, we must look for a common everyday word which stands in a similar relation to “cask”. The key idea is that a cask is a specific kind of large container for liquids, especially one made of wood. A very close everyday synonym for this is “barrel”.

Step-by-Step Solution:
Step 1: Understand “Thread : String”. A string is formed using threads or can be described as a length of thread used as a cord. The two words are very closely related; string is the main noun used for the practical object. Step 2: Understand the meaning of “Cask”. A cask is a large container, usually wooden, used for storing liquids such as wine, beer, or other beverages. Step 3: Examine the options. “Barrel” is a common word for a large cylindrical container, often exactly the same kind of object that “cask” refers to. “Disc”, “Wallet”, and “Box” are not special names for this type of wooden liquid container. Step 4: Therefore, “Cask : Barrel” has a close type–synonym or near synonym relationship, in the same way that “Thread : String” shares a strong everyday association as related forms of the same basic item.

Verification / Alternative check:
We can also think of the relationship as “specialised or technical term” to “more common everyday term”. “Cask” is a slightly more specialised word, while “barrel” is the simpler and more commonly used word. Similarly, “thread” is the finer element that we often describe as “string” when it is used as a cord. None of the other options, such as “Disc” or “Wallet”, can be used interchangeably with “cask”. A disc is a flat circular object, a wallet is for money, and a box is a general container but not specifically the same as a cask.

Why Other Options Are Wrong:
• Disc: Refers to a flat circular object such as a compact disc or plate, not a liquid storage container. • Wallet: A small case used to carry money or cards, unrelated to large wooden containers for liquids. • Box: A general container, usually rectangular; it does not capture the special meaning of a cask used for liquids.

Common Pitfalls:
Some learners overthink this question and search for a very complicated analogy such as part–whole. In exam settings, however, many analogies are based on simple synonym or near synonym relationships. Another common mistake is to pick “Box” because it is also a container. However, cask refers specifically to a barrel like vessel for liquids, so the precise and accepted match in standard verbal reasoning is “Barrel”.

Final Answer:
The correct word that completes the analogy is Barrel.