What is the Big O of the following code segment? (assume $n$ refers to the number of elements being processed, or a value that otherwise represents the problem size.)
for(int a = 0; a < n; ++a) {
for(int b = 0; b < 22; ++b) {
//do some constant O(1) operation here
}
}
O($2^n$)
O($n^2$)
O(n)
O(1)