On an Oscilloscope, the channel 1's vertical position or offset control allows you to...
Select one:
O a. Change the Range or Volts/div used to display channel 1.
O b. Adjust channel 1's zero volt 'ground' marker and resultant waveform up and down on the Scope's display.
O c. Add a DC offset voltage to the circuit under test.
O d. Move the entire display of the scope in the vertical direction.
O e. Finely tune the thickness of the lines used in channel 1's plot.