Which best describes the difference between a seismograph and seismogram? A. A seismograph is a written record of volcanic eruptions, while a seismogram is a written record of earthquakes. B. A seismograph records tectonic activity, while a seismogram records volcanic activity. C. A seismograph is the instrument that detects and records volcanic activity, while a seismogram is the written record of that activity. D. A seismograph is the instrument that detects and records movements within the earth, while a seismogram is the recording.