Why did urban riots break out in Us cities in 1967?

2 July 1967, Newark, New Jersey, US, Factors that contributed to the Newark Riot: police brutality, political exclusion of blacks from city government, urban renewal, inadequate housing, unemployment, poverty, and rapid change in the racial composition of neighborhoods.

Explanation:

powers  are  denied  to the  national governmentin three distinct ways: some  powers, such as the  power  to levy duties on exports or prohibit the freedom of religion, speech, press, or assembly, are expressly  denied  to the  national government  in the  constitution.

d) iowa i believe is the answer