D. seismograph
Explanation:
Seismograph is the instrument that used to study earthquake. safely established onto the floor of the soil so that once the soil shakes, the entire unit shakes with it however for the mass at the spring, which has inaction and stays in the identical placed. as the seismograph shakes beneath the mass, the recording machine on the mass information the relative movement among itself and the rest of the tool, subsequently recording the ground motion
