The label of the object consisting of the two items could be the union of their features in this case.4 Going back to (1)-(3), the two bracketed phrases in each should be analyzed as having the same internal structure.
if ka is assumed to have no category feature, the labels of the two bracketed phrases in (1) repeated below are the unions of the features of the wh-phrase and those of ka: ( the ka-phrases are both categorially NPs due to the category feature of the inside noun dare.