Final answer:
The question lacks the necessary information to accurately determine the units needed for the stores. Additional data on demand and inventory levels would be required to make a proper calculation.
Step-by-step explanation:
The question does not provide enough information to determine the exact number of units needed for all stores. In real-world scenarios, determining how many units are needed for all stores would require additional data such as the demand of each store and the inventory levels in each warehouse. Without such information, it is not possible to choose between options a) 110 units, b) 120 units, c) 140 units, or d) 150 units.
Assuming this is a simple addition problem and the two referenced options (c. 10 units and d. 15 units) were parts of the equation, you would combine them to get a total of 25 units, which is not an answer option. However, this seems to be out of context as it does not align with any of the answer choices provided (a, b, c, or d).
Therefore, we must clarify the question or receive more information to provide a correct and precise response to how many units are needed for all stores. If the student has specific data on supply needs, they should present that information for an accurate calculation.