I'm not sure I understand your sample correct answers, so this might not be what you're after. (I don't know why there is an answer (Sam E, Kylie) and an answer (Sam E, Kirsten)), but

In cell L4:
=D4&E4&F4&G4&H4&I4&J4&K4
Copy down

In some column in row 4:
=IF(COUNTIF($L$4:$L$19,L4)>1,"Can't Win ("&C4&")","")
Copy down