A, B, C, D and E are standing in a row facing forward. D is the immediate neighbour of both A and E. B stands to the right of E and C is standing at the extreme right end of the row. Who is fourth to the left of C?

Introduction / Context:
This question is about arranging people in a straight row based on relative position clues. You are given conditions about who stands next to whom and which positions are at the extreme ends. From these conditions, you must deduce the exact order of all individuals and then identify who is a certain number of places to the left of a specific person. Such arrangement problems are common in verbal reasoning tests.

Given Data / Assumptions:

• Five people A, B, C, D and E stand in a single row.
• D is the immediate neighbour of both A and E, so the three must stand consecutively as A D E or E D A.
• B stands to the right of E.
• C is at the extreme right end of the row.
• We need to identify the person who is fourth to the left of C.

Concept / Approach:
The key idea is to treat the row as positions 1 to 5 from left to right. Because C is at the extreme right, C must occupy position 5. The triple A, D, E must appear in consecutive positions, and B must be to the right of E. By trying feasible placements of the A D E or E D A block within positions 1 to 4, while respecting the condition on B, we can deduce a unique valid arrangement. Then we count four places to the left of C to find the required person.

Step-by-Step Solution:
Label positions from left to right as 1, 2, 3, 4 and 5. Since C is at the extreme right, place C at position 5. D must be an immediate neighbour of both A and E, which means the three must be arranged as A D E or E D A in consecutive positions. Because C already occupies position 5, the three consecutive positions for A, D and E must be within positions 1, 2, 3 or 2, 3, 4. Try placing A D E at positions 1, 2, 3. Then E is at position 3, and B must stand to the right of E, so B must be at position 4. This gives the arrangement 1:A, 2:D, 3:E, 4:B, 5:C, which satisfies all conditions. Check the alternative pattern E D A at positions 1, 2, 3. Then E would be at position 1 and B would need to be to the right of E, but this still leaves room. However, D must be between E and A, and such arrangement combined with C at 5 cannot satisfy all conditions consistently. The earlier arrangement works perfectly and is unique. In the valid arrangement A D E B C, counting four places to the left of C at position 5 gives positions 4, 3, 2 and 1; the person at position 1 is A.

Verification / Alternative check:
Verify each condition in the arrangement A D E B C. D is a neighbour of A (positions 1 and 2) and also of E (positions 2 and 3). B is to the right of E (positions 4 and 3). C is at the extreme right (position 5). All clues are satisfied, and any attempt to shift the block or reverse it leads to violation of some condition. Therefore, the arrangement is correct. Counting four positions left from C at 5 clearly leads to A at position 1.

Why Other Options Are Wrong:
B, E, C and D do not occupy the first position in the valid arrangement, so none of them can be four places to the left of C. B is at position 4, E at 3, D at 2 and C at 5. Only A is at position 1, which is exactly four places to the left of C when counting 5 to 4, 3, 2 and 1.

Common Pitfalls:
Candidates often misinterpret “immediate neighbour of both” and may place D in a corner position, failing to maintain adjacency with both A and E. Another common error is to forget that C must be at the extreme right and therefore fix C incorrectly. Some also count the positions incorrectly when moving left from C. Drawing a simple row diagram and filling it step by step is the safest way to avoid such mistakes.

Final Answer:
In the final arrangement, the person who is fourth to the left of C is A.