Nudibranchs Usually Have Two Rhinophores

Nudibranchs usually have two rhinophores. However, if they had a single rhinophore, it could still carry out the function of two rhinophores, and with similar effectiveness, if this single rhinophore

A) had two branches, one directed to the left, the other to the right.
B) had two branches, one directed toward the head, the other directed toward the tail.
C) was as long as two rhinophores placed end to end.
D) had cilia whose power strokes directed water away from the surface of the slug.
E) was located within the mantle cavity.