Two sets are equal if they contain identical elements. However, two sets are equivalent if they contain the same number of elements (but not necessarly the same elements) Give an example of two sets that are neither equal nor equivalent.

Choose the correct answer below:

A. {2} and {3,4}
B. {a,b} and {a,c}
C. {5} and {4+1}
D. {1,2,3} and {1,2,1 +2}