A. dinoflagellate (correct answer)
B. diatoms
C. chrysophyta
D. xanthophyta
Answer analysis: Most shellfish poisoning is caused by the accumulation of toxic dinoflagellate in shellfish. Shellfish poisoning refers to food poisoning caused by eating some shellfish containing toxins. Common shellfish that cause poisoning are mussels, clams, snails, oysters and scallops. There are different kinds of toxins in shellfish, such as paralysis, diarrhea (liver poison) (clam poison) and so on. Paralysis is the most common characteristic of poisoning symptoms.