During an earthquake or any ground movement, a seismograph would produce an output called seismogram in which we could see the recording of the motion of the ground in the three Cartesian axes (x, y, and z). A seismograph has a special device called seismometer that is extremely sensitive to up and down motions of the earth and this device can be understood by visualizing a weight hanging on a spring.
Since two earthquakes are producing different relative strength, therefore the correct answer to this would be:
“The seismograms produced during the two earthquakes will be very different. The stronger one will have a larger amplitude than the weaker one.”