In the following question, a word has been written in four different ways out of which only one is correctly spelt. Select the correctly spelt form of the word meaning "the act of killing an important person for political or religious reasons".

Introduction / Context:
This spelling question asks you to identify the correct form of a commonly used but often misspelt English word. The word refers to the act of killing an important person, such as a political or religious leader, usually for ideological or financial reasons. Correct spelling is essential in competitive exams because it shows careful attention to detail and a strong command of written English.

Given Data / Assumptions:

We are testing the spelling of the word pronounced /əˌsæsɪˈneɪʃn/.
The word means the act of deliberately killing a famous or important person.
Several options include extra or missing letters, especially in the middle of the word.
Only one option corresponds to the standard dictionary spelling used in formal English.

Concept / Approach:
The correct spelling builds from the base "assassin" plus the suffix "-ation". The base word "assassin" has the letter sequence a-s-s-a-s-s-i-n with a double s in the middle. When we add "-ation", we get "assassination" with two double-s clusters: assa-ss-in-ation. Any option that changes the number or order of s letters, or adds unnecessary vowels, will be incorrect. Always identify the root and the suffix to guide your spelling choices.

Step-by-Step Solution:
Step 1: Recall the base noun "assassin" meaning a person who kills an important figure. Step 2: Add the common noun-forming suffix "-ation", which turns the action into "assassination". Step 3: Check option C "Assassination" and see that it preserves the correct root "assassin" and adds "-ation" without altering the letter sequence. Step 4: Examine option A "Asassination": it has only one "s" after the initial "A", which breaks the double-s pattern in the root. Step 5: Examine option B "Assasination": it misses one "s" in the middle, giving a weaker ss pattern and deviating from "assassin". Step 6: Examine option D "Assaissination": it wrongly introduces an "i" after "ss", creating a non-standard and confusing cluster. Step 7: Examine option E "Assassinattion": it includes a double "t" in "tton", which is not part of the standard spelling.

Verification / Alternative check:
You can cross-check by understanding related forms: "assassin", "assassinate", "assassination". Each of these keeps the double-s pattern in the middle after the initial "ass". We never see "asassinate" or "assasinate" in correct English. Also, many dictionaries and exam preparation books confirm "assassination" as the only standard spelling. Recognising the pattern "assassin + ation" will help you remember it long-term.

Why Other Options Are Wrong:
Option A Asassination lacks the required double "ss" after the initial a and therefore does not match the root assassin.
Option B Assasination drops one "s" in the central cluster and is a very common but incorrect exam spelling.
Option D Assaissination introduces an extra "i" and becomes an unrecognised form with a confusing vowel sequence.
Option E Assassinattion adds an extra "t", which is not present in the correct word and breaks the neat "-ation" ending pattern.

Common Pitfalls:
Candidates often get confused by the repeated "s" letters and try to simplify the spelling by dropping one of them, resulting in incorrect forms like "assasination". A practical strategy is to learn the root assassin and note that both the root and the derivative assassination contain two pairs of consecutive "ss": as-sa-ss-in-ation. Visualising or writing this pattern a few times can help fix the correct spelling in your memory.

Final Answer:
The correctly spelt word is "Assassination".