Choose odd one w.r.t. sexuality.
Monecious Plants (mono meaning one) have male and female reproductive organs on the same plant. In other words, they are hermaphrodites. The organs may or may not be on the same flower (i.e. the flowers can be perfect or imperfect. Eg. Coconut, cucurbits, chara, etc.
Dioecious Plants (di meaning two) have either male OR female flowers (not both). As a result, plants are either male OR female. Imperfect flowers only. Eg. Papaya, cannabis, etc.
So, the correct option is 'Papaya'.