Which group within kingdom Protista probably gave rise to sponges? On what evidence do you base your answer?

Which group within kingdom Protista probably gave rise to sponges? On what evidence do you base your answer?|||Flagellates broadly speaking, choanoflagellates more narrowly. Sponges have cells called choanocytes ("collar cells") whose beating flagella create the water flow that feeds the sponge's suspension-feeding needs.