When you hold your hand palm-up, the atmosphere exerts a force of about 800 N on the palm of your hand. Comparing this force with

Question

I. the force on the back of the hand,
II. the force on the palm when you are holding your hand vertical,
III. the force on the palm when it is palm-down

A) It is equal to I but different from II and III
B) it is different from I, II, and III
C) It is equal to II and III but different from I
D) They are all equal

Why would they be different? What is Pascal's principle?