Helen wants to find the surface area of the solid pictured on the left, so she constructs a net of the solid pictured on the right.

A rectangular prism with a length of 30 millimeters, width of 18 millimeters, and height of 9 millimeters. 2 triangular sides have a base of 30 millimeters and height of 27.3 millimeters. 2 triangular sides have a base of 18 millimeters and height of 30.9 millimeters. A net has a rectangular base and 4 triangular sides.

Which statement best describes her work?
Helen’s net is incorrect because she forgot to include the shared rectangular face where the upper and lower solids are joined together.
Helen’s net is correct because she included the front, back, left, right, and bottom faces of the solid.
Helen’s net is incorrect because she treated the figure as a single rectangular pyramid instead of a composite shape.
Helen’s net is correct because she reorganized the solid as a triangular prism.