In the following question, four words are given. Select the correctly spelt word from the options.

Introduction / Context:

Spelling questions in competitive examinations check a learner's familiarity with standard English word forms. Many scientific and technical words follow regular patterns that can help you remember the correct double consonants or vowel combinations. The word in focus here is distillation, a common term in chemistry and everyday language that refers to a process of purifying a liquid. Recognising the correct arrangement of letters is an important part of building a strong vocabulary.

Given Data / Assumptions:

- Four options are given: distilation, distillation, destillation, and destilation.

- Only one of these represents the standard accepted spelling in modern English.

- There is no trick with regional variants; the test expects the common international spelling.

- We assume that the meaning relates to the process of distilling liquids and not to any specialised brand or name.

Concept / Approach:

The word distillation comes from the verb distil or distill, depending on regional spelling, with the noun formed by adding the suffix tion. For such nouns, when the base verb ends in a consonant followed by a short vowel, the consonant is often doubled before adding the suffix. In this case, the pattern distill plus ation leads to distillation, with a double l and a single s. By comparing each option with this expected structure, we can quickly eliminate incorrect forms.

Step-by-Step Solution:

Verification / Alternative check:

To verify the answer, you can recall where you have seen the word in textbooks or dictionaries. It appears in chemistry chapters on separation techniques and is always spelled with dis followed by till and then ation. You can also break the word into syllables dis til la tion and note that the double l occurs at the end of the second syllable. Checking online or printed dictionaries will confirm that distillation is the only standard form among the given options.

Why Other Options Are Wrong:

Distilation omits one l, which is a common error when learners are unsure about double consonants. Destillation introduces an unnecessary e after d, transforming dis into des, which changes the base and is not supported by etymology. Destilation combines both errors, making it doubly incorrect. None of these forms appear in standard dictionaries as valid spellings for the noun referring to the purification process.

Common Pitfalls:

Many students struggle with whether to double consonants before common suffixes such as tion, ment, and ness. Another pitfall is misremembering the prefix dis, which can be incorrectly replaced with des or disi. A good strategy is to link the noun distillation back to the verb distil or distill so that the repetition of the letter l feels natural. Writing the word several times and pronouncing it in syllables can also reinforce the correct pattern.

Final Answer:

The correctly spelt word is distillation, which is the standard English spelling of the noun.