Because of d
ifferences in the humans body's internal pressure and the ocean's, it is essential that a diver returning to the surface ascends slowly or they will suffer a painful condition known as the "bends."
a)differences in the human body's internal pressure and the ocean's, it is essential that a diver returning to the surface ascends slowly or
they
b)the difference between the human body's internal pressure and the ocean's, it is essential that a diver returning to the surface ascend slowly or
they
c)the difference in the human body's internal pressure and
that of the ocean, it is essential that a diver returning to the surface ascends slowly or he -- What does "that" refer to: difference or pressure ?
d)differences in the human body's internal pressure and that of the ocean, it is essential that a diver returning to the surface ascend slowly or
they
e)the difference between the internal pressure of the human body and that of the ocean, it is essential that a diver returning to the surface ascend slowly or he--
Correct