Question

state income taxes can be:
1 flat or progressive.
2 progressive only.
3 flat only.
4 neither flat nor progressive.

Explanation:

State income tax structures can be either flat (where the same tax rate applies to all income levels) or progressive (where tax rates increase with income). So option 1 correctly states this, while the others are incorrect as they limit or misstate the possible structures.

Answer:

1. Flat or progressive.