Answer: C.
Step-by-step explanation: Commutative property is when the numbers in the equation are swapped and C. has 34 + 14= 14 + 34 which swaps 34 + 14 into 14 + 34. The numbers in the equation are swapped.
It isn’t B. Because it mixes up numbers instead of swapping them.
It isn’t D. because it is a proper equation with no swapping. Same thing with A.
Hope I helped! Have a good day!