Using executive dashboard requires:

A$.$ Less expertise than performing ad$-$hoc data analysis with OLAP$/$BI tools

B$.$ More expertise than performing ad$-$hoc data analysis with OLAP$/$BI tools

C$.$ Same level of expertise as for performing ad$-$hoc data analysis with OLAP$/$BI tools

D$.$ Knowledge of SQL

E$.$ Both B and D$.$