Answer to 6M1 has a mistake

[imLew]

The answer currently reads:

There are now 5 paths from X to Y. The three paths from the original DAG, and 2 new paths introduced by V

1. X→Y
2. X←U→B←C→Y
3. X←U→B←C←V→Y
4. X←U←A→C→Y
5. X←U←A→C←V→Y

We want to keep path 1 open, because that is the causal path of interest. Paths 2 and 3 are already closed, because B is a collider. Paths 4 and 5 are open because A is a fork. In the original DAG, we could close either A or C; however, in the new DAG, C is a collider. Therefore, if we conditioned on C, we’d be opening up a new path through V. Therefore, if we want to make > inferences about the causal effect of X on Y, we must only condition on A.

I've highlighted the path I think is incorrect. Path 5 is not open because in it C is a collider.