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 word.

Introduction / Context:
Spelling questions test the learner's familiarity with standard English spellings, especially for commonly used but sometimes tricky words. The word here is "humorous", which describes something funny or amusing. Only one of the options presents the correct spelling, and the others contain extra letters, missing letters, or misplaced letters.

Given Data / Assumptions:

• Target word: Humorous.
• Options: Humourosu, Humorus, Hlumorous, Humorous.
• The task is to choose the correctly spelt word.
• We assume standard British or American English where "humorous" is spelled with one "m" and ends with "ous".

Concept / Approach:
The concept tested is basic spelling and visual recognition of correct letter order. "Humorous" is derived from "humour" (British) or "humor" (American), plus the suffix "ous". When forming the adjective, the correct spelling is "humorous", not "humourous". The approach is to compare each option with the known correct pattern and eliminate those with obvious irregularities such as extra letters or missing vowels.

Step-by-Step Solution:
Step 1: Recall the correct spelling: H U M O R O U S. Step 2: Check Option D: "Humorous". This matches exactly with the standard spelling we know. Step 3: Option A: "Humourosu" adds an extra "u" and "s" at the end, making it incorrect. Step 4: Option B: "Humorus" is missing the second "o", so it does not follow the correct pattern. Step 5: Option C: "Hlumorous" has an extra letter "l" at the beginning and is clearly wrong. Step 6: Therefore, the correctly spelt word is Option D, "Humorous".

Verification / Alternative check:
A practical check is to recall common related forms such as "humour" and "humorous" or "humor" and "humorous". Dictionaries and textbooks consistently show "humorous" with the letters arranged as H U M O R O U S. Any extra letters, missing vowels, or consonant changes immediately signal an incorrect spelling. If a learner has seen the word in context – for example, "a humorous story" – the correct form will also look familiar visually, which helps confirm the choice.

Why Other Options Are Wrong:
Option A: "Humourosu" is incorrect because of the added "su" at the end, which does not match English spelling patterns for adjectives of this type. Option B: "Humorus" drops one "o" and therefore does not reflect the proper vowel sequence in the word. Option C: "Hlumorous" places an unnecessary "l" after the initial "H", making the spelling clearly wrong.

Common Pitfalls:
Students sometimes confuse "humorous" with "humourous" because the noun form "humour" in British English includes a "u". However, the correct adjective form removes that extra "u". Another common error is to rely on how a word sounds and spell it phonetically, which may lead to missing vowels. The best way to avoid such mistakes is to read widely, pay attention to spellings in quality texts, and maintain a list of frequently tested words in competitive exams.

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