Which of the following symbols is critical to the theme of heritage in “Everyday Use?” The TV show, Maggie’s burns, Wangero’s sunglasses, or The churn top.

That would be the butter churner. This is a device that Dee thinks is a quaint reminder of black heritage. The irony is that Dee and Mother use the butter churner. There is nothing quaint about it, they need it for "everyday use."