Give the correct matching for the following pairs:

A. O(log n)     1. Selection sort
B. O(n)         2. Insertion sort
C. O(nlog n)    3. Binary search
D. O(n^2)       4. Merge sort

codes: 
     A   B   C   D
a.   3   1   2   4
b.   3   1   4   2
c.   1   3   4   2
d.   1   4   3   2