HARTFORD, Conn. (AP) — Parents and policy makers across the nation have been plunged anew into a debate over whether face coverings should be optional or a mandate when schools reopen. U.S. health officials recommended this week that children mask up in school this fall. They blamed the delta variant of the coronavirus. Some states are likely to heed the federal government’s guidance and require masks. Others are leaving the decision up to parents. The controversy is unfolding at a time when many Americans are at their wits’ end with pandemic restrictions. Others fear their children will be put at risk by those who don’t take the virus seriously enough.