Final answer:
The statement about the racial composition of protesters at Martin Luther King Jr.'s speech represents a fact based on historical records, relating to the 1963 March on Washington, where approximately 300,000 people, two-thirds of whom were Black, participated.
Step-by-step explanation:
Understanding the Racial Composition at Martin Luther King Jr.'s Speech
The statement that 'one-fourth of the protesters at Martin Luther King Jr.'s speech were white' primarily represents a fact based on historical records (Option B). This factual assertion is supported by historical evidence and the extensive documentation surrounding the 1963 March on Washington for Jobs and Freedom. During this historic event, it is recorded that approximately 300,000 people attended, of which two-thirds were Black, confirming the presence of a significant number of white participants as well. Hence, the statement is not merely an opinion, anecdotal observation, or a hypothesis, but a reflection of the demographic data from one of the pivotal moments in the Civil Rights Movement.