Answer the following question given this paragraph: 

People divide up the seas into five oceans. But they are really all interconnected. Even so, they are all very different. This ocean is near a shore and is obviously in a cold region. It appears to be a good habitat for whales! No matter what, the oceans have a huge influence on the planet, locally and as a whole.


Q: We divide up the earth's seas into five what, which are really all interconnected?

 Choices:

- lakes

- continents

- ecosystems

- oceans

A:
oceans
