In case of emergency (e.g., serious accident with great blood loss) which blood group could be safely transfused?

Blood group AB can take blood from which blood groups ?

For safe blood transfusion

For safe blood transfusion

For safe blood transfusion

For safe blood transfusion

Blood group A can donate blood to which blood group ?

In an accident there is great loss of blood and there is no time to analyse blood group. Which blood group can be safely transferred?