The correct option is
C All of the above
Hippocampus is commonly called as seahorse.
A. All seahorses have their horse like head held at right angle to their body.
B. Seahorses have a prehensile tail which means that their tail is able to grasp or hold the objects.
C. Seahorses swim with the help of their dorsal fins. Their pectoral fins are much reduced and located behind their eyes.
Hence, all the options are correct. So, the correct answer is 'All the above'.