Which of the following is triploblastic and monoecious?
Flatworms (e.g., Taenia) are triploblastic and monoecious (sexes are not separate).
Ctenoplana (Ctenophora) is diploblastic and monoecious.
Wuchereria (Aschelminthes) and Nereis (Annelida) are triploblastic and dioecious.