drop down list to decide which range my graph will plot

Question

I have dropdown in E1 cell as follows

1. Expander 1 eff
2. Expander 2 eff
3. Pump eff
4. AirInTemp
5. CO2PumpOutPressure,

if i select the first three in the drop down menu, i want the range i want to plot in the graph in the same sheet to be A1:B40 if i select the last two in the drop down menu, i want the range i want to plot in the graph in the same sheet to be A1:B6

i tried AI, it told me to create Range1 & Range2 with those ranges, and asked me to assign macro to a cell, i couldn't because when i right click on a cell, i doesn't tell me to assign a macro