Exercise
To which group is D3 isomorphic?
Z/6Z
Z/2Z × Z/3Z
S3
No.
For this group is commutative and D3 is not.
No. This group is the same as Z/6Z.
Right. Viewing D3 as the group of the triangle,
we see that it permutes the three vertices in all possible ways,
just like S3.