The best answer would have to be
B.) The volume, density, and salinity of the ocean water
The external ear structure is called the Pinna.
The Pinna helps to channel sound waves into the ear.
Many animals have the ability to move their pinna towards the direction of sound.
I have attached an image of a dog's ear to show you the external structure called the Pinna.
I hope this helps! I'm happy to answer any other questions you might have :)
[Image sourced from: https://www.msdvetmanual.com/dog-owners/ear-disorders-of-dogs/ear-structure-and-function-in-dogs]
Answer:
As the generations are increasing or gets much over time, we have a more likelihood of seeing a response to natural selections as the favourable alleles are going to be moved from one generation to the next while those that are not favourable would be eliminated over generations.
If the new host gives allowance for early reproduction and ease of access then the generations each year would rise.