ExErCISE 6.1. For a finite abelian group, one can completely specify the group by writing down the group operation table. For instance, Example 2.7 presented an addition table for Z6. (a) Write down group operation tables for the following finite abelian groups: 5, L5, and L3 (b) Show that the group operation table for every finite abelian group is a Latin square; that is, each element of the group appears exactly once in each row and column (c) Below is an addition table for an abelian group that consists of the elements [a, b, c, d]; however, some entries are missing. Fill in the missing entries