A. Porifera
A.
B. Cnidaria
B.
C. Platyhelminthes
C.
D. Annelida
D.
Correct Answer: B
সঠিক উত্তর: B
Explanation
ব্যাখ্যা
Nematocysts are specialized stinging cells found in the tentacles and body wall of organisms belonging to the phylum Cnidaria (also known as Coelenterata). They are used for capturing prey and defense.