Which statement represents a case of gerrymandering?

The Republican-controlled legislature of Michigan adjusts its political districts to keep Republicans in office.
The Republican-controlled legislature of Texas adjusts its political districts to account for an increase in population in urban areas.
The Democratic-controlled legislature of Illinois eliminates polling places in rural areas, making it more difficult for rural voters to participate in elections.
The Democratic-controlled legislature of California decides to ignore the results of a population shift and keep its current political borders in place.