Answer :
Looking at a blood type chart:
Patients with AB+ blood can receive ANY type of blood.
Patients with AB- blood can receive ANY type of blood with RH factor minus.
Since we don't know if the patient has AB+ or AB- blood, we can only use blood that would work for both, which would be those with RH factor minus.
The only RH factor minus blood from your choices is AB minus, so that's the only one that could be given to both AB+ and AB- patients.
Patients with AB+ blood can receive ANY type of blood.
Patients with AB- blood can receive ANY type of blood with RH factor minus.
Since we don't know if the patient has AB+ or AB- blood, we can only use blood that would work for both, which would be those with RH factor minus.
The only RH factor minus blood from your choices is AB minus, so that's the only one that could be given to both AB+ and AB- patients.