Letter from Birmingham Jail, composed by Martin Luther King, Jr. from his cell in the Birmingham Jail Cell, is a seminal document that established the moral foundations for the non-violent civil rights demonstrations of the Birmingham Campaign. Other seminal US Documents include Washington's Farewell Address, the Gettysburg Address, and Roosevelt's Four Freedoms speech.

In the context of this statement, what does the word seminal mean?

A. A speech or document that is not important and quickly forgotten
B. Having a strong influence on ideas, works, events, etc., that come later : very important and influential
C. A religious document