11) G

1 – Correct

If a lot of re-offenders are being sent to prison, this would definitely cause the decline to occur.

2 – Correct

If a lot of the original offenders die, this would cause the decline to occur.

3 – Correct

Harsher sentencing would prevent some of the original offenders from doing any more offences, causing the decline to occur.

Since all statements are correct, G is the answer.