Islam became part of North African cultures due to the geographical location and due to the spread of refugees from Saudi Arabia and other countries in Asia. North Africa was one of the first countries that Islam spread to other than Asia.
I believe the correct answer from the choices listed above is option D. The difference between a seismograph and seismogram is that a seismograph is the instrument that detects and records volcanic activity, while a seismogram is the written record of that activity. Hope this answers the question.