Answer:
C.- ↓Holding Cost = ↑Economic Order Quantity
Step-by-step explanation:

Economic Order Quantity = square root of (2DS/H)
Where:
Demand and setup are in the dividend part, if they increase, the EOQ increase.
Holding cost goes in the divisor, if they increase the EOQ decrease
A- FALSE ↑Holding Cost ≠↑Economic Order Quantity
B- FALSE ↑Demand ≠↑EOQ
C.- Correct ↓Holding Cost = ↑Economic Order Quantity
The divisor is lower, so the value increase.