The March on Washington had a significant impact on the Civil Rights Movement, particularly because it helped to galvanize public support and draw attention to the demands for civil rights reform. The most direct effect mentioned in your options is:
• It led to the passage of the Civil Rights Act of 1964.
The March on Washington on August 28, 1963, where Dr. Martin Luther King Jr. delivered his famous "I Have a Dream" speech, played a crucial role in creating momentum for the Civil Rights Act, which was passed the following year.