Did you not read the "Forum Rules" in the "new users" forum?
"(5) When you post a question include any work that you have been able to do and show us
where you are stuck. When responding to a member helping you, you must at least try to follow
their advice/hints/work. We are here to help you, not do your problems for you. If you make a
habit of not showing work we will be forced to assume you are trying to cheat."
Do you know what a "group" is? Do you know what "surjective" or "injective" mean? If you expect to be able to answer this problem, you certainly should but you give no indication that you do.
Even if you do not know how to start this problem stating those definitions will help us point out how to use them.