Consider the following statements:

1. A death sentence awarded by a sessions court can be executed in case the convict does not approach high court within specified time limit.

2. A person cannot be hanged until he has been provided opportunity to exhaust all legal remedies.

3. A delay in disposal of clemency petition can be a ground for double jeopardy.

4. Convict can approach SC in case of mental unsoundness of death penalty convict.

How many of the above is/are correct ?