Public awareness of the Selma march was important because:
D. It helped the public realize there was a need for the Voting Rights Act.
Step-by-step explanation:
By 1965 the most important issue remaining in the civil rights movement was the one of the Voting Rights Act which was the primary concern of the black population of the time.
Although the black population did have a right to vote by then, but it was important to end the discriminatory practices against them in the voting and election processes to make the democracy truly representative of their culture.
Thus the march being publicized made people realize the need for it.