(N/A) For a compound to be aromatic,it must satisfy the following conditions: $(1)$ It must be cyclic,$(2)$ It must be planar,$(3)$ It must have a complete conjugation of $\pi-$electrons,and $(4)$ It must follow Huckel's rule,i.e.,it must have $(4n+2)$ $\pi-$electrons,where $n$ is an integer $(n = 0, 1, 2, \dots)$.
$(i)$ The compound is heptafulvene. It is not aromatic because the $sp^3$ hybridized carbon atom at the exocyclic double bond breaks the continuous conjugation of the ring.
$(ii)$ The compound is cyclopentadiene. It is not aromatic because it has a $sp^3$ hybridized carbon atom in the ring,which prevents the continuous conjugation of $\pi-$electrons. Additionally,it has $4$ $\pi-$electrons,which does not satisfy Huckel's rule $(4n+2)$.
$(iii)$ The compound is cyclooctatetraene. It is not aromatic because it is non-planar (it adopts a tub-shaped conformation) and it has $8$ $\pi-$electrons,which does not satisfy Huckel's rule $(4n+2)$.