[单选题]
The gravitational force betwzd** ;it(u/stpqhxih/:x k r 5een two objects is proports: yto6hp uh80dtn6ior zp 56/ional to
A. the distance between the two objects.
B. the square of the distance between the two objects.
C. the product of the two objects.
D. the square of the product of the two objects.
