In this spelling based English question, four versions of the adjective meaning calm and not easily upset are given; select the correctly spelt word “unruffled”.

Introduction / Context:
This question checks accurate spelling of a common English adjective used to describe a calm and undisturbed person or situation. The word unruffled is frequently used in reading comprehension passages and descriptive writing. Correct spelling is essential not only in exams but also in professional communication, where errors can distract the reader and lower the perceived quality of the writing.

Given Data / Assumptions:
The main facts are as follows:

• The intended word is unruffled, which means calm, not disturbed, or not emotionally upset.
• Four differently spelt versions are offered: unraffled, unruffled, unrufled, and unrafled.
• We must identify the standard dictionary spelling.
• The context is general English usage, not any specialised field.

Concept / Approach:
The adjective unruffled is formed from the verb ruffle, which means to disturb or to make uneven. The prefix un gives the opposite sense, so unruffled literally means not ruffled. The correct spelling uses the base ruffled with a double f and the ed ending. Therefore the correct adjective has the form un plus ruffled, giving unruffled with two f letters and two l letters. Variants that replace ff with f or change the vowel pattern are incorrect.

Step-by-Step Solution:
Step 1: Recall that the base verb is ruffle, and its past participle is ruffled with two f letters. Step 2: Add the negative prefix un to form unruffled. Step 3: Examine option b, unruffled. It shows un plus ruffled, with double f and double l, which matches the expected structure. Step 4: Look at option a, unraffled, which uses a instead of u and ffled instead of ffl ed, leading to a completely different and incorrect form. Step 5: Consider option c, unrufled, where only one f and one l are present. This breaks the base spelling of ruffled. Step 6: Consider option d, unrafled, which again changes the vowel and reduces the consonant doubling, so it is wrong. Step 7: Conclude that option b is the only correctly spelt word.

Verification / Alternative check:
To verify, think of example sentences such as She remained unruffled even during the crisis. In dictionaries and well edited texts, the spelling always appears as unruffled with double f and double l. Any other variation looks unusual and is not used. This consistency in usage confirms that unruffled is the correct spelling. Also, following the pattern of similar words like muffled or shuffled reinforces this choice.

Why Other Options Are Wrong:
Option a, unraffled, is wrong because it changes the vowel after r and does not match the original base word ruffle. Option c, unrufled, incorrectly removes one f and one l, creating a non standard and awkward spelling. Option d, unrafled, also drops necessary letters and changes the vowel, so it cannot be accepted as correct English. None of these forms appear in standard dictionaries or formal writing.

Common Pitfalls:
Many learners struggle with consonant doubling in English spelling, especially with ff, ll, and tt patterns. They may try to simplify by writing a single consonant, which leads to forms such as unrufled. Another pitfall is guessing based on how the word sounds rather than on known spelling rules. To avoid such mistakes, it is helpful to notice patterns in related words and to remember that the prefix un does not change the spelling of the base, it simply attaches to it.

Final Answer:
The correctly spelt word is unruffled, which means calm and not easily disturbed.