Question

how do bivalves obtain food? radula to scrap the sea floor siphons to filter feed tentacles to catch food

Explanation:

Bivalves are mollusks with two - part shells. They use siphons to draw in water, filter out food particles like plankton and organic matter from the water, and then expel the filtered water. A radula is a feeding structure in some other mollusks like gastropods, not bivalves. Tentacles are used by some other organisms like cnidarians for catching food, not bivalves.

Answer:

Siphons to filter feed