From the given options, select the word that cannot be formed using the letters of the word EXPERIMENTAL.

Introduction / Context:
In this question, the base word is EXPERIMENTAL and you must find which one of the options cannot be formed from its letters. Several options share letters with the base word and seem quite similar at first glance. The test is whether you can detect a letter that is missing from the base word or a letter that would need to be used more times than available. This type of precise letter based checking is an important part of verbal reasoning practice for competitive exams.

Given Data / Assumptions:
Base word: EXPERIMENTAL.
Letters available: E, X, P, E, R, I, M, E, N, T, A, L.
Options: PARENT, RELAX, METER, METHANE.
We assume that letters are case insensitive and we cannot introduce any new letters beyond those in the base word, nor can we exceed the available count of each letter.

Concept / Approach:
The approach is to list the letters and their counts from EXPERIMENTAL, then inspect each option. If an option uses a letter that the base word does not have, or uses a letter more times than permitted, it cannot be formed. Because EXPERIMENTAL already contains a rich mix of consonants and vowels, most options will seem plausible, so it is crucial to look carefully for letters like H that may be missing.

Step-by-Step Solution:
Step 1: Count the letters in EXPERIMENTAL. E: 3, X: 1, P: 1, R: 1, I: 1, M: 1, N: 1, T: 1, A: 1, L: 1. Step 2: Check PARENT. PARENT requires P, A, R, E, N, T. All these letters appear in EXPERIMENTAL with sufficient counts, so PARENT can be formed. Step 3: Check RELAX. RELAX requires R, E, L, A, X. The base word has R, E, L, A and X, so RELAX is possible. Step 4: Check METER. METER requires M, E, T, E, R. EXPERIMENTAL has M, T, R and three Es, so METER can be formed easily. Step 5: Check METHANE. METHANE requires M, E, T, H, A, N, E. The letters M, E, T, A and N are present, but the base word does not contain H at all. Therefore METHANE cannot be formed from EXPERIMENTAL.

Verification / Alternative check:
We can verify this by rechecking the letters of EXPERIMENTAL: E, X, P, E, R, I, M, E, N, T, A, L. There is no H in this list. Since METHANE requires H, it is impossible to form this word. Meanwhile, PARENT, RELAX and METER each use only letters present in EXPERIMENTAL, and none of them needs any letter more times than the base word provides. This confirms that METHANE is the unique invalid option.

Why Other Options Are Wrong:
PARENT is valid because P, A, R, E, N and T are all present and within allowed counts.
RELAX is valid since R, E, L, A and X occur in EXPERIMENTAL.
METER is valid as M, two Es, T and R are available; in fact, there are enough Es to cover the two needed in METER.
These three options can be formed, so they are not the answer to the question asking for the word that cannot be formed.

Common Pitfalls:
Many candidates glance at METHANE and immediately feel it is similar to words like METER and PARENT and may assume it is also possible. However, overlooking a single new letter such as H is a common mistake. Another pitfall is to look only at vowels and ignore certain consonants, which leads to incorrect conclusions. To avoid these errors, always scan each option for any letter that does not appear at all in the base word before checking repeated letters and counts.

Final Answer:
The word that cannot be formed from the letters of EXPERIMENTAL is METHANE, because the base word does not contain the letter H.