If there is a line from step A to step B, you can use step A’s output variables in step B’s options. In short: if there’s a line between, we can pass data.In this case, Start has a line to all other steps. So we can use Start’s variables in A, B, C, and D. A has a line to B, so B can also use A’s variables. However, there’s no line between A and C, so there’s no way to pass data between those steps. If you want to allow A to pass variables to C, then you need to move C after A and combine it into one chain of four steps in a row.