I would believe the answer to be (a) since the effect has to do with wind force movement
The spread began in the 7th to 9th century, originally brought to North Africa under the Umayyad Dynasty. Trade networks were extensive, spanning through north and west Africa which created a medium in which islam peacefully spread through the merchant class.
The space time continuum meaning that time travel would be very much possible if humans could break the barrier of the 4th dimension