Stop in for a cup of coffee

One of my standard questions to maint tech applicants is the scenario of a conveyor jammed and you need to reverse it to clear. Which two wires do you switch. Some of the answers and explanations are literally laugh out loud funny. I usually pose this question after they explain to me what excellent industrial electricians they are. Don’t even get me started on explaining a 4-20ma loop!
just need to switch any two......