In the word "OBSERVANT", the first letter is interchanged with the ninth, the second with the eighth, the third with the seventh, and the fourth with the sixth, while the fifth letter remains in its original position. What will be the new arrangement of letters after performing these position reversals?

Introduction / Context:
This aptitude question tests your understanding of letter arrangement and positional interchanging inside a given English word. Instead of simply reversing the word "OBSERVANT", the question describes a specific rule for swapping positions of letters from the beginning and the end, while keeping the middle letter fixed. Such problems are common in bank, SSC, and other competitive exams to check accuracy, visualization, and stepwise reasoning with alphabetic data.

Given Data / Assumptions:

• The original word is "OBSERVANT".
• It has 9 letters in total.
• The first letter becomes the ninth, the second becomes the eighth, the third becomes the seventh, and the fourth becomes the sixth.
• The fifth letter remains unchanged.
• No letters are added or removed; only their positions are rearranged.

Concept / Approach:
The approach is to treat the word as a sequence of positions from 1 to 9 and then apply the swapping rule carefully. Essentially, the described rule is equivalent to reversing the entire word, because in a 9 letter word, interchanging 1 with 9, 2 with 8, 3 with 7, and 4 with 6 naturally leaves the middle (5th) letter fixed. However, instead of jumping directly to this observation, it is safer in exam conditions to map each position step by step, so that no letter is misplaced or skipped.

Step-by-Step Solution:
Step 1: Write the original word with positions: 1 O, 2 B, 3 S, 4 E, 5 R, 6 V, 7 A, 8 N, 9 T. Step 2: Apply the rule that the 1st becomes the 9th and the 9th becomes the 1st. So positions 1 and 9 swap letters O and T. Step 3: Swap the 2nd and 8th positions. So B at position 2 and N at position 8 are interchanged. Step 4: Swap the 3rd and 7th positions. So S at position 3 and A at position 7 are interchanged. Step 5: Swap the 4th and 6th positions. So E at position 4 and V at position 6 are interchanged. Step 6: The 5th letter R remains unchanged because the rule explicitly says the fifth letter stays in its original position. Step 7: After performing these swaps, rewrite the word from position 1 to 9: 1 T, 2 N, 3 A, 4 V, 5 R, 6 E, 7 S, 8 B, 9 O, which gives the word "TNAVRESBO".

Verification / Alternative check:
Another quick way to verify is to recognize that the described operation is exactly the same as reversing the full 9 letter word. If we reverse "OBSERVANT" directly, we also get the letters in the order T N A V R E S B O. This confirms that "TNAVRESBO" is correct. Cross checking with the original mapping ensures that no letter is missed and each position is handled correctly.

Why Other Options Are Wrong:
Option A "TNAVERSBO" misplaces the letters E and R and does not match the strict positional swaps described in the question.
Option C "NTAVERSBO" has the first letter as N instead of T and again contains the wrong internal order of letters.
Option D "VANTRESBO" starts with V, which cannot appear at the first position after the specified swaps. The pattern of letters is inconsistent with either the stepwise mapping or the simple reverse of the original word.
Option E "NTAVRESOB" has both incorrect starting and ending letters, so it clearly does not match the required arrangement.

Common Pitfalls:
A common mistake in such questions is to perform only some of the swaps or to misread the instruction about the middle letter remaining unchanged. Some candidates quickly guess by trying to visually reverse the word and accidentally rearrange internal letters incorrectly. Others may forget to keep the fifth letter fixed and instead swap it as well. Working slowly with clear position numbers and writing down intermediate steps helps avoid these errors.

Final Answer:
The correct new arrangement of letters is TNAVRESBO.