In this spelling question, four alternatives are given; choose the word which is correctly spelt in standard English for the term related to medical treatment of bones.

Introduction / Context:
English spelling questions often test common scientific and medical terms, because these words are long, contain multiple vowels and are easy to misspell. Here the target word is the term that refers to the medical speciality dealing with bones and joints. You have to pick the correctly spelt word out of four similar-looking options. Such questions reward careful observation and familiarity with standard dictionary forms used in Indian and British English.

Given Data / Assumptions:

• Four similar spellings are provided: orthopeadic, orthopadic, orthopaedic, orthopedic.
• Only one of these represents the standard correct spelling expected in most competitive exams that follow British-based usage.
• The question is purely about spelling, not about meaning differences between British and American English.

Concept / Approach:
In British and Indian English, the usual spelling of the word is “orthopaedic” with the sequence “ae” in the middle. In American English, a common variant is “orthopedic” without the “a”. Competitive exams in India overwhelmingly prefer the British or International spelling patterns. Therefore, we must focus on locating the option that shows the correct arrangement “ortho + paed + ic” with all letters in the right order and with no extra or missing vowels. We then reject any form where letters are omitted, misplaced or doubled incorrectly.

Step-by-Step Solution:
Step 1: Break the target word mentally into parts: “ortho” (relating to bones or straight) + “paed” (relating to children or treatment) + “ic”. Step 2: Examine option a) “orthopeadic”. The vowel sequence here is “oea”, which is not the standard “ae” sequence used in the correct form. Step 3: Examine option b) “orthopadic”. This spelling misses the letter “e” after “pa”, giving “padic” instead of “paedic”. It is therefore incorrect. Step 4: Examine option c) “orthopaedic”. This matches the standard British spelling with “ortho” + “paedic” and the crucial “ae” combination. Step 5: Examine option d) “orthopedic”. Although this form is acceptable in American English, typical Indian and British English exam standards treat “orthopaedic” as the correct reference spelling. Step 6: Select option c) “orthopaedic” as the correctly spelt word.

Verification / Alternative check:
You can verify using memory triggers from textbooks and hospital boards that often use the phrase “orthopaedic surgeon” or “department of orthopaedics”. In almost all such contexts in Indian print material, you will see the “ae” in the middle. Also, if you are familiar with related words like “paediatrician” (for children's doctor), you will recognise the same “paed” pattern. This reinforces that “orthopaedic” is the form that aligns with the expected exam standard, making it the safest choice in this question.

Why Other Options Are Wrong:
“Orthopeadic” has an incorrect vowel sequence and does not match any standard variety of English. “Orthopadic” drops a crucial letter and produces a non-standard variant. “Orthopedic” is a valid American spelling, but most Indian competitive exams follow British-based spellings, so it is not treated as the “correct” answer in this typical question style. The test setter expects recognition of “orthopaedic” as the conventional form.

Common Pitfalls:
A common mistake is to overthink the British versus American variation and choose the option that looks more familiar from movies or online content, which often use American spelling. Another trap is to misread similar clusters of vowels when reading quickly under exam pressure. Training yourself to break long words into meaningful parts and linking them to related words like “paediatrics” helps you avoid such errors. Slow down slightly and visually match each letter cluster rather than guessing from overall appearance.

Final Answer:
The correctly spelt word is orthopaedic.