An intellectual or artistic movement that breaks with tradition and therefore seems ahead of its time is called ; literally, it means "advance guard in a military formation."

An intellectual or artistic movement that breaks with tradition and therefore seems ahead of its time is called Avant-garde ; literally, it means "advance guard in a military formation."

Explanation:

Avant- garde generally means bringing new ideas, experiments or methods in fields such as art, literature or music. It means to introduce novel experiments and ideas.

In the French language, avant- garde means to foreguard. The term avant-garde was initially used in the military to describe highly skilled soldiers  who went ahead of the rest of the army to explore the terrain and warn of possible danger.

i would say b. research typically uses a variety of sources