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:

A B C D

activity time per unit (min) : 0.25, 0.33, 0.2, 0.5

number of workers: 2 3 2 4

Which resource(s) has (have) the highest utilization?

Both Type A and Type D Workers

Type D Worker

Type A Worker

Type B Worker

Type C Worker