A manager wants to show that salespeople who wear red sell the most products. Which of the following issues is most likely to bias the results?

Group of answer choices

Weather throughout the days of sales

The car the salesperson drives is red

Those who wear red may be more outgoing

The colors of the local university

The heights of the various salespeople

To study the safety of a car in accidents at a set speed, it would be important for the researcher to consider the following to avoid bias:

Group of answer choices

Whether the driver lives in the city or rural areas

The type of guidance or GPS system included in each car

The size and type of cars being tested

The color of the cars tested

The age of the driver