Final answer:
The factor in the scenario is Frosting, and the levels are New and Existing frostings that are being evaluated by the mini donut factory.
Step-by-step explanation:
The factor in the given scenario is Frosting; this is what's being changed or tested in the mini donuts. The levels of this factor are the New and Existing frostings, as these represent the different conditions or variations of the factor that will be evaluated. Options a, c, and d are not related to the specific test being described, as they refer to aspects such as location, time of day, and customer preference which are not mentioned as variables in this particular scenario.