Koi prefer dissolved oxygen levels between 7 and 10 ppm. What does this tell you about the dissolved oxygen concentration inside the cells of a koi's gills?

Please pick one of the options below:

A: The cells in the gills have a dissolved oxygen level of less than 7 ppm so that oxygen will leave the cells.
B: The cells in the gills have a dissolved oxygen level between 7 and 10 ppm so that oxygen will leave the cells.
C: The cells in the gills have a dissolved oxygen level greater than 10 ppm so that oxygen will enter the cells.
D: The cells in the gills have a dissolved oxygen level of 9 ppm so that oxygen will leave the cells.