How was islam able to cross the sahara desert in the eighth century?

When metal tools where made.hope this mark this as the brainiest!

Well, by looking at your question and also your answers that you have provided your answer to your question is going to be choice a) protestants.this is because they had been a member of or follower of any of the western christian churches. these churches had been separated  from the roman catholic  church and they follow the principles  of reformation, and baptism, and also the luthern churches, and finally  the  presbyterian.i hope this mark me as brainiest