In living donation, the following blood types are compatible:
Donors with blood type A... can donate to recipients with blood types A and AB
Donors with blood type B... can donate to recipients with blood types B and AB
Donors with blood type AB... can donate to recipients with blood type AB only
Donors with blood type O... can donate to recipients with blood types A, B, AB and O (O is the universal donor: donors with O blood are compatible with any other blood type)
So,
Recipients with blood type O... can receive a kidney from blood type O only
Recipients with blood type A... can receive a kidney from blood types A and O
Recipients with blood type B... can receive a kidney from blood types B and O
Recipients with blood type AB... can receive a kidney from blood types A, B, AB and O (AB is the universal recipient: recipients with AB blood are compatible with any other blood type)