The Graphical Approach to Analyzing Data to Determine What Causes

The graphical approach to analyzing data to determine what causes differences between groups has the following problem(s) :

A) It is difficult to anticipate all the graphs that might be useful.
B) Two dimensional graphs are limited in the information they convey.
C) When multiple variables are considered simultaneously, higher dimension graphs (greater than two dimensions) become difficult to interpret.
D) Only a and b are involved.
E) All of the above are involved.