In the bubble sort algorithm, which code accomplishes swapping values in elements at positions index and index + 1?

A. list[index] = list[index + 1]
list[index + 1] = list[index]
B. list[index + 1] = list[index]
list[index] = list[index + 1]
C. list[index] = temp;
list[index] = list[index + 1];
temp = list[index + 1];
D. temp = list[index];
list[index] = list[index + 1];
list[index + 1] = temp;

Answer: D