The answer is A, is it sort of "commoditized" the products made with it, allowing the products to become cheaper and mass produced.
Answer: The statement here is absolutely correct.
Explanation: In order to understand that why this answer is correct, I will provide you with a little insight of the history. The term vassal originated with the emergence of feudalism in the middle ages, at that time all the land was the possession of the ruling Aristocrat. The Aristocrat will reward their lands to vassals expecting that they will protect the Aristocrat in return. Whenever, some vassal will fight for the Aristocrat, the Aristocrat will provide him with a land and expect him to protect the the Aristocrat for rest of his life.
I have no clue what this is, but I hope someone else can give you an answer