Answer: B. [tex]3+(1+11)=15[/tex]
Step-by-step explanation:
1. By definition, the associative property of addition is:
[tex](a+b)+c=a+(b+c)[/tex]
2. Therefore, if you have the following expression:
[tex](3+1)+11=15[/tex]
You apply the Asociative property of addition by regrouping the numbers as following:
[tex]3+(1+11)=15[/tex]
3. Then, you can conclude that the correct option is B.