Identify the algorithm used in the following code.

void algo(int arr[], int n){
for (int i = 0; i < n-1; i++) {
for (int j = 0; j < n-i-1; j++){
if (arr[j] > arr[j+1]) {
int temp = arr[j];
arr[j] = arr[j+1];
arr[j+1] = temp;
}
}
}
}

a. Bubble sort, O(n^2)
b. Insertion sort, O(n^2)
c. Merge sort, O(n log n)
d. Quick sort, O(n log n)

a. Bubble sort, O(n^2)