In the following question, from the given alternative words, select the word which cannot be formed using the letters of the word CALCULATING.

Introduction / Context:
This is a word-formation question from verbal reasoning. You are given a base word, CALCULATING, and asked to decide which of the listed option words cannot be formed using its letters. This tests your attention to detail, your ability to count repeated letters correctly and your skill at quickly checking whether each required letter is available in sufficient quantity in the base word.

Given Data / Assumptions:

- Base word: CALCULATING.- Available letters: C, A, L, C, U, L, A, T, I, N, G.- Option words: GAIN, TANING, TAIL and CULT.- Each letter of the base word can be used only as many times as it actually appears in CALCULATING.

Concept / Approach:
The key is to count the frequency of letters in the base word and compare those frequencies with the letters required by each option. If an option asks for a letter that is not present at all, or it requires more copies of a letter than exist in the base word, then that option cannot be formed. A systematic count avoids mistakes that happen when you rely only on quick visual scanning.

Step-by-Step Solution:
Step 1: List letter counts in CALCULATING. The word contains: C (2 times), A (2 times), L (2 times), U (1 time), T (1 time), I (1 time), N (1 time), G (1 time).Step 2: Check the word GAIN. It requires G, A, I and N. The base word contains G (1), A (2), I (1) and N (1), so GAIN can be formed.Step 3: Check the word TAIL. It requires T, A, I and L. The base word contains T (1), A (2), I (1) and L (2), so TAIL can also be formed.Step 4: Check the word CULT. It requires C, U, L and T. The base word has C (2), U (1), L (2) and T (1), so CULT can be formed without any shortage of letters.Step 5: Check the word TANING. It requires T, A, N, I, N and G. Notice that N appears twice in TANING, but in CALCULATING there is only one N.Step 6: Because the base word provides only one N, it is impossible to form TANING which needs two Ns, even though all the other letters (T, A, I and G) are present.

Verification / Alternative check:
Another way to confirm is to physically cross out letters of CALCULATING as you use them for each option word. For TANING you would use the single N in the base word once, but you would immediately see that there is no second N available. For all the other option words, the crossing-out process completes smoothly with no shortage. This reinforces that TANING alone cannot be formed from the given letters.

Why Other Options Are Wrong:
GAIN, TAIL and CULT are all perfectly achievable from CALCULATING. None of them requires any letter more times than it appears in the original word. Rejecting any of those would mean you have miscounted or overlooked a letter. TANING is the only word that demands two Ns, which the base word does not provide.

Common Pitfalls:
Many candidates focus only on whether each letter is present and forget to check how many times it appears. This leads to mistakenly accepting words that require a repeated letter. Others confuse similar letters or read the option word too quickly. Taking a few extra seconds to count repetitions carefully usually eliminates such errors.

Final Answer:
The word that cannot be formed from the letters of CALCULATING is TANING.