Which comments are examples of constructive feedback?

ADon't use dialogue when you write. It's childish.

B If you summarized the go-kart story instead, you could get to the real conflict sooner.

CWhen using dialogue, you don't always need to write "he said" and "she said." The context can often indicate who is talking.

DThis essay is OK, but it doesn't have any action. Chess tournaments are boring, so I don't think anyone will want to read this.