Identify the location and function of the following structures:
$(i)$ Comb plates
$(ii)$ Flame cells

• A
  Comb plates: Found in Ctenophora,used for locomotion. Flame cells: Found in Platyhelminthes,used for osmoregulation and excretion.
• B
  Comb plates: Found in Cnidaria,used for digestion. Flame cells: Found in Annelida,used for respiration.
• C
  Comb plates: Found in Porifera,used for water transport. Flame cells: Found in Nematoda,used for reproduction.
• D
  Comb plates: Found in Echinodermata,used for protection. Flame cells: Found in Mollusca,used for circulation.