An oligarchy is ruled by few people therefore, an oligarchy can not have over 50 people ruling though most oligarchies have much smaller number of leaders.
One of the inventions in 1400s was improved gunpowder, which gave the imperial powers more military power.
Also, the development of ship building has enabled the Portuguese to establish and maintain a number of trade posts in Africa, which were a beginning of their colonial invasions.
I believe the answer is b. false.
