关于SAT 2物理 理想气体定律,谢谢解答~

题目

关于SAT 2物理 理想气体定律,谢谢解答~
which of the following statements is NOT A correct assumption of the model of an ideal monatommic gas?
A.The atoms are constantly moving
B.The atoms' collisions with one another create pressure directly on the container of the gas.
C.The collisions between atoms are elastic.
D.The only significant force acting on the atoms are those which are applied as a result of collisions.
多谢!
答案是B。求解释~

答案

D.The only significant force acting on the atoms are those which are applied as a result of collisions.