Option B
The body is not spotted nor does it have an elongate beak or an erect triangular dorsal fin.
Select

There are 2 species recorded in Tanzania: Stenella attenuata and Stenella longirostris. Look for either an elongated beak and tall erect dorsal fin (in Stenella longirostris, the Spinner Dolphin) or spots on the side (in Stenella attenuata, the Bridled Dolphin).