The answer is letter A or two. It is a known fact that fish swim on the water by contracting and then relaxing their myomeres – their muscle blocks – on each side of their body. This process helps them to bend their body from one side to another which creates wave throughout their body to help them move across the water. However,
it is worthy to mention that the waves which flow through their body are the ones which make them thrust forward – this happens when they forcefully move their tails back and forth so it could provide the main propulsion for their forward motion. A fish can swim with other fish, but sources point out that only two fish can swim side by side while the others are positioned somewhere else.