When using weighted variables to establish a performance index, what cross-check of your weighting process is important to remember? Question 3 options: a) positive and negative weights should add up to zero b) all weights should add up to one c) there should be an exactly equal number of both positive weight values and negative weight values; however, the sum is not important d) the top priority indicator should have the lowest value, similar to the sport of golf; the lower score is a better score