How can variable costing be used for decision making in a manufacturing company

a$)$ Indicate rather it is normally best to use absorption or variable method in the following situations:

i$)$ Setting prices in the long run $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

ii$)$ Controlling costs by upper management $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

iii$)$ Production planning in the short run $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

Analyzing profitability with sales mix