Final answer:
Marine teleosts are hyperosmotic to seawater.
Step-by-step explanation:
The statement that is true about marine teleosts is b. They are hyperosmotic to seawater. Fish in saltwater environments, like marine teleosts, have to cope with the high solute concentration of salts in their environment by excreting excess salt. This enables them to maintain a higher concentration of solutes in their bodies compared to the surrounding seawater, making them hyperosmotic to seawater.