The correct option is
C Cercaria
Schistosoma, is commonly known as blood flukes. These are parasitic flatworms responsible for a highly significant group of infections in humans termed schistosomiasis. After infection, the cercaria enters into the liver and blood where they become an adult and migrate into the intestine where female lays an egg. These eggs then expelled out through urine or feces. The miracidium is liberated from the egg and penetrates the intermediate host snail tissues
So, the correct answer is 'Cercaria'