Respuesta :
Diving means it is moving down so it would be a negative value.
You would need to multiply the rate by the number of seconds it dives, so you would have -9x for that part.
The dolphin started at 10 feet below sea level which would be written as -10.
To find the elevation you would need to add both parts together, which would give you:
y = -9x -10
The answer is B.