Answer:
c. That salt water is more dense than fresh water
Explanation:
Semantic memory is a type of memory that stores general knowledge that we have learnt over the course of our lives. General knowledge refers to the facts, ideas, meaning and concepts a person has. They are generally combined with the experiences a person has.
Here, Gina is remembering the first time she swam in the ocean. This memory is of the episodic type. She remembers that her father told her that salt water is more dense than fresh water. This fact was entwined with her episodic memory.
Hence, the fact that she remembers that salt water is more dense than fresh water is semantic memory.