Which of the following best describes the difference between differential stress and confining pressure?

a. Under confining pressures, the stresses on the sides are greater than the force of gravity. Stresses are the same on all sides for differential stress.
b. In differential stress, the stresses on the sides are greater than the force of gravity. Stresses are the same on all sides for confining pressure.
c. In differential stress, the force of gravity is higher than in confining stress.
d. Both confining pressure and differential stress have stresses applied to a rock in one direction, which is greater than the force of gravity as a whole.
e. In confining stress, the force of gravity is higher than in differential stress.