Consider the following four-step process: each product needs to go through activities A, B, C, D sequentially. There are 4 types of workers (A, B, C, D), who are responsible for the 4 activities, respectively. The process time required for each activity and the number of workers for each type are given in the following table. For example, there are 2 Type A workers, and each of them spends 0.25 minutes to process a unit during activity A.

The following data are available for the four steps:

Suppose the steps in activity D can be done easier with new approach, and the activity time is reduced by 50% (i.e., reduced to 0.25 min per unit) now. Assume everything else remains the same, what is the capacity of the process? Choose the closest number if needed.

8 units/minute

12 units/minute

16 units/minute

10 units/minute

9 units/minute