ANS:B - remains unchanged.

To determine the impact on the economic order quantity (EOQ) when the demand for an item is trebled and the order cost is reduced to one third, let's first recall the formula for EOQ: EOQ=2DS​​/H Where:

• D = Demand rate (units per time period)
• S = Ordering cost per order
• H = Holding cost per unit per time period

Now, let's consider the changes:

1. If the demand (D) is trebled, it becomes 3D.
2. If the ordering cost (S) is reduced to one third, it becomes 1/3​S.

Substituting these changes into the EOQ formula, we get: EOQ=2(3D)(1/3​S)/H​​=2DS​​/H This shows that the EOQ remains unchanged despite the changes in demand and ordering cost. Therefore, the correct option is: Remains unchanged.