From the given options, choose the word that cannot be formed using the letters of the word THUMBING.

Introduction / Context:
This verbal reasoning question checks your ability to form words from a given collection of letters. You are given a base word and asked which option cannot be formed using the letters of that base word. Such questions test attention to detail, letter counting, and the ability to track repeated letters. The challenge is to verify each option carefully rather than relying on intuition or quick visual similarity. Mastering this type of question helps in many competitive examinations where word formation and letter manipulation are common reasoning themes.

Given Data / Assumptions:
Base word: THUMBING.
Letters available: T, H, U, M, B, I, N, G.
Options: THING, MIGHT, HAUNT, THUMB.
We assume each letter in the base word can be used only as many times as it appears there. No extra letters can be introduced, and no letter can be repeated beyond its available count.

Concept / Approach:
The standard approach is to list or mentally note the letters of the base word and their frequencies, then check each option letter by letter. If an option uses a letter that is not present in the base word, or uses some letter more times than its available count, that option cannot be formed. This process is methodical and does not rely on guesswork. For speed, you can spot obviously absent letters first, since those immediately disqualify an option.

Step-by-Step Solution:
Step 1: Write down the letters in THUMBING. T, H, U, M, B, I, N, G, each available once. Step 2: Check the option THING. Letters needed: T, H, I, N, G. All of these appear in THUMBING, and no letter is repeated more than once. So THING can be formed. Step 3: Check the option MIGHT. Letters needed: M, I, G, H, T. Each of these letters is present in THUMBING, and each appears at most once. So MIGHT can also be formed. Step 4: Check the option HAUNT. Letters needed: H, A, U, N, T. The base word THUMBING has H, U, N, and T, but it does not contain the letter A at all. Because A is missing, HAUNT cannot be formed from THUMBING. Step 5: Check the option THUMB. Letters needed: T, H, U, M, B. All are present in THUMBING exactly once, so THUMB can be formed.

Verification / Alternative check:
To verify the conclusion, we can recheck the base letters and confirm there is no A in THUMBING. The letters are T, H, U, M, B, I, N, G. There is clearly no A. Since HAUNT critically depends on A, and all other options consist solely of letters that do exist in the base word, our reasoning holds. Additionally, no option uses a letter more times than available, so the only violation happens in HAUNT. This confirms that HAUNT is uniquely invalid.

Why Other Options Are Wrong:
THING is valid because all five letters T, H, I, N, and G are present in THUMBING and are used only once each.
MIGHT is valid because M, I, G, H, and T all appear in the base word and their counts do not exceed the available letters.
THUMB is valid because T, H, U, M, and B all come directly from THUMBING without any missing or extra letters.
Therefore these three options can be formed and are not the required answer.

Common Pitfalls:
A frequent mistake is to overlook a single missing letter such as A in this example, especially when the rest of the letters appear to fit well. Candidates sometimes focus only on the first few letters and assume the whole word is possible. Another pitfall is forgetting to limit repetition; however in this particular question each relevant letter appears only once, which keeps counting simple. To avoid errors, always scan for letters that are completely absent from the base word before performing detailed counting. This quick filter often reveals the impossible option very efficiently.

Final Answer:
The only option that uses a letter not present in THUMBING is HAUNT, because it requires the letter A, which the base word does not contain. Hence HAUNT cannot be formed and is the correct answer.