Which graph represents a step function?

On a coordinate plane, a piecewise function has 3 lines. The first line has an open circle at (negative 3, 2) and goes up through (negative 4, 4) with an arrow instead of an endpoint. The second line has a closed circle at (negative 3, 0) and continues horizontally to an open circle at (1, 0). The third line has a closed circle at (1, negative 2) and goes down to an open circle at (5, negative 5).

On a coordinate plane, a piecewise function has 3 lines. The first line has an open circle at (negative 5, negative 3) and continues horizontally to a closed circle at (negative 2, negative 3). The second line has an open circle at (negative 2, negative 1) and continues horizontally to a closed circle at (2, negative 1). The third line has an open circle at (2, 1) and continues horizontally through (5, 1) with an arrow instead of an endpoint.

On a coordinate plane, a step graph has horizontal segments and vertical segments that are each 1 unit long. An open circle starts the step function at (negative 5, negative 4) and a closed circle stops the step function at (5, 4).