Final answer:
The clade Lophotrochozoa is characterized by a lophophore, a feeding structure with ciliated tentacles, and a trochophore, which is a larval stage; thus, the correct answer is C: a crown of ciliated tentacles for feeding; larval stage.
Step-by-step explanation:
The superphylum Lophotrochozoa includes organisms that are characterized by having either a lophophore, a specialized feeding structure, or a trochophore stage of larval development. The lophophore is a crown of ciliated tentacles surrounding the mouth that is used for feeding.
A trochophore is a larva that is free-swimming and characterized by two bands of cilia. Given this information, the characteristic of the clade Lophotrochozoa are features such as a lophophore, which is a crown of ciliated tentacles for feeding, and a trochophore, which is a larval stage. Therefore, the answer to the student's question is C: a crown of ciliated tentacles for feeding; larval stage.