Assertion (A) is true: In tropical countries like India, the long axis of an open-sided poultry house must be aligned strictly East to West.
Reason (R) is true: The sun follows an overhead path from east to west; an East-West orientation ensures that the sun's direct rays fall primarily on the roof rather than entering through the open sidewalls, thereby preventing excessive solar heat buildup inside the shed.
Because Reason (R) directly explains the rationale for Assertion (A), both are true and (R) is the correct explanation of (A).

Option analysis:

• Correct. Both (A) and (R) are true and (R) is the correct explanation of (A).
• Incorrect because (R) is indeed the exact reason for (A).
• Incorrect because (R) is true.
• Incorrect because (A) is true.