Which of the following properties is used in when combining like terms?  $3x^{2}y+5-x^{2}y$  $=(3-1)x^{2}y+5$  $=2x^{2}y+5$ 
选项为:A:commutative property  B:associative property  C:distributive property  D:private property  请回答其中一个选项.