What is the efficiency of an algorithm with a complexity of N log N$?$

a$.$

The efficiency of N log N is equal to N$^2,$ as they both have the same growth rate.

b$.$

The efficiency of N log N is worse than N$^2,$ as it has a higher growth rate.

c$.$

The efficiency of N log N is better than N$^2,$ as it has a lower growth rate.

d$.$

The efficiency of N log N and N$^2$ cannot be compared as they represent different types of algorithms.