As a general impact over all of Africa, foreign invaders, typically from Europe, initially seemed to have a positive impact in the sense that they introduced public schools and basic hygiene, but the also had many negative impacts because eventually, in the 18-1900's when many African nations became independent countries and forced the Europeans out, they were left with little government, political, or economic skills which is why many of the African nations of the modern day are still considered developing countries.
<u><em>The so-called</em></u> "<u>commercial transition</u>", <u><em>by which foreign influence had an impact on social, religious and economic development in Africa</em></u>, <u>was completed in West Africa before it affected East Africa</u>.
<u><em>The correct answer is</em></u>: <u>East Africa, and West Africa</u>.
Islam came to the Southeast Asia, first by the way of Muslim traders along the main trade-route between Asia and the Far East, then was further spread by Sufi orders and finally consolidated by the expansion of the territories of converted rulers and their communities.