The answer is <u>"weigh advantages and disadvantages".</u>
Explanation:
Whenever you are analyzing any problem, it is important to consider what are advantages and disadvantages to make any changes to a particular situation. As in the given question when you are going to consider whether it is cost effective to add a salad bar to a school lunch menu or not, you should weigh advantages and disadvantages of that. By using this step , you will get better option.