Formula of a triangle: length*breadth/2
It is B, because that is how they produce their scientific name
The human digestive system can fail if you eat something harmful, and it can break down nutrients, techinically the digestive system can stop working if you get something like Gastoparesis, which stops the movement of food through the digestive system.
Although the dolphin lives in the sea, it is not a fish - it's a mammal.
It makes the most sense if you read it aloud.