When does the Phillips curve look like this?Description of diagram is below the diagram. The diagram has unemployment on the horizontal axis and inflation on the vertical axis. There is a place marked on the horizontal axis marked as UN. There is a line starting at the origin that goes out and up from the origin at a 45 degree angle and continues indefinitely. There is nothing else on the diagram. Group of answer choices When people are not changing their expectation of inflation. It never looks like this. When people have adaptive expectations. When people have rational expectations