The method TagSupport.findAncestorWithClass() can be used...
The answer to this is Any type of tag (Tag, IterationTag, BodyTag)
But I thought the answer will be only for tags extending Tag Support. The hint they have given is as follows
Remember these two points #1. Any type of tag (Tag, IterationTag, BodyTag) can be nested within another. #2. The method findAncestorWithClass() is a static method defined in TagSupport class provided for convenience: public static final Tag findAncestorWithClass(Tag from, java.lang.Class klass);
Thus, it is not necessary to implement the BodyTag interface or extend from the TagSupport or the BodyTagSupport classes to use this method.