Eva sees a dolphin 3.2 meters below sea level and a bird 47/10 meters above sea level. Which of the following expressions represents the vertical distance between the dolphin and the bird?​

For this case we have:
The bird is at a positive distance of meters above sea level.
The dolphin is at a negative distance of 3.2 meters below sea level.
Being the surface of the sea the point 0, to find the vertical distance between the bird and the dolphin, we must add the module of each distance, that is to say:

Thus, the vertical distance between both animals is

Option C: None of the above