The noun phrase invisible hair tonic is structurally ambiguous. Identify the constituent structure tree representation below for this phrase which represents the possible meaning that the "tonic is for invisible hair' $($hair that cannot be seen$)($i$.$e$.$ the humorous interpretation$).($Hint: For this question ignore the fact that the phrase structure rules we have developed so far for English are not complete enough to generate structures for these phrases. Simply focus on the obvious differences in constituent structure and$/$or syntactic category labels represented in each tree structure to find the best structure associated with the intended meaning given above.$)$

a$)$

c$)$