Heatmap data represents mutual correlations of variables within a data set; however, there are times that using heatmap data does not help with your visualization efforts. Which of the following underscores this concern?
a. Don't use it when you have only a few indicators.
b. Don't use it when you have multi-dimensional data.
c. Don't use it when you want to show relationships.
d. Don't use it when you want to highlight clusters and patterns.