Answer:
D) guilds
Explanation:
New members would usually start as apprentices, and learn from other master members during a relatively long period of time. Apprentices were usually teenagers when they entered a guild and the learning period lasted up to 14 years. Once the apprentice mastered the crafting techniques, he became a master member.
Guilds were very important and powerful in medieval Europe from the 11th to 16th century. They were able to limit specialized labor, set prices and define tools and techniques.
