Four words are given, out of which only one is spelt correctly in standard English. Choose the correctly spelt word.

Introduction / Context:
Spelling questions test a learner familiarity with the correct written forms of commonly used English words. Here, four similar looking variants are provided, and only one matches the standard spelling of the word that means hostile or violent behaviour. Knowing correct spellings is important not only for examinations but also for formal writing, where such errors can create a negative impression. The task is to recognise the proper arrangement of letters in the target word.

Given Data / Assumptions:

• Four spellings are given: Aggression, Agression, Aggretion, Aggresion.
• We are asked to choose the correctly spelt word.
• All options are visually similar, with small differences in the number of g and s letters and the vowel arrangement.
• The intended word is the noun meaning hostile or attacking behaviour.

Concept / Approach:
The correct spelling of the word meaning hostile or violent behaviour is aggression. It comes from the Latin root aggredi, meaning to attack. In English, the standard spelling uses double g and double s, forming aggression. The incorrect options typically drop one of these consonants or change the middle portion of the word. Our approach is to recall or confirm the standard spelling pattern ag plus gress plus ion, with both g and s doubled in the middle, and then match it with the options.

Step-by-Step Solution:
Step 1: Recall that the correct spelling of the word is aggression, which is commonly seen in phrases like acts of aggression. Step 2: Break the word into parts: ag + gress + ion, noting that both g and s are doubled. Step 3: Examine option A: Aggression. It has two g characters and two s characters in the middle, matching the standard form. Step 4: Examine option B: Agression. This version has only one g, which is incorrect. Step 5: Examine option C: Aggretion. This not only reduces the s letters but also changes the core part to retion, which does not match the original word. Step 6: Examine option D: Aggresion. This version uses a single s and is therefore incorrect.

Verification / Alternative check:
We can confirm our choice by thinking of related words that share the root gress, such as progress, congress, and digression. The pattern gress with double s is familiar in many English words. The noun form aggression follows this same pattern, with ion added to form a noun. Standard dictionaries and textbooks always show aggression with double g and double s. When we compare this with the options, only Aggression in option A fits the established pattern. The other variants are typical exam traps, created by removing or changing one consonant.

Why Other Options Are Wrong:
Agression: This spelling has only one g after the initial a, which does not match the correct structure of the word.
Aggretion: This version changes the middle part to retion, which refers to a different pattern entirely and does not correspond to the word about hostile behaviour.
Aggresion: Here the problem is the single s in the middle. The correct word requires two s characters, not one.
Aggression: This option correctly uses both double g and double s and matches the established spelling in English.

Common Pitfalls:
Many learners are confused by double consonants in English spelling, especially when words contain both double g and double s. A common mistake is to drop one consonant and still feel the spelling looks right, particularly in words that are heard more often than seen in writing. To avoid such errors, it is helpful to notice the pattern in related words and to practise spelling tricky words by writing them out several times. Keeping a personal list of difficult spellings is also useful for exam preparation.

Final Answer:
The correctly spelt word among the options is Aggression.