I received a reject error code ND-517-01 I understand one of my dependents, I claimed 3, may not be claimed, I want to know which one. Where can I find it?

[HelenC12]

Rejection Code IND-517-01 indicates that the first Dependent listed on your Form 1040 has been claimed  or they themselves have already filed a Tax Return. Source: Rachel_W

[honey badger]

Thank You!!!!