Which among the following statements are true for unisexual flowers?
(i) they possess both stamen and pistil
(ii) they possess either stamen or pistil
(iii) they exhibit cross-pollination
(iv) unisexual flowers possessing only stamens cannot produce fruits
A. (i) and (iv)
B. (ii), (iii) and (iv)
C. (iii) and (iv)
D. (i), (iii) and (iv)