What was the effect of the 16th amendment?
a. it allowed workers to take industrialist to court for proper wages and benefits.
b. it granted congress the power to tax incomes.
c. it permitted women the right to take business to court for equal pay.
d. it declared settlement houses to be illegal.

The effect of the 16th Amendment was that b) It granted Congress the power to tax incomes. The 16th Amendment to the United States Constitution allowed Congress to levy taxes without apportioning it to that specific state or basing it on the United States Census (apportioning it to the state and according to their respective numbers) and this included all taxes except income tax.

Abolition of slavery

4.a depression is the answer