Which person is demonstrating a positive attitude?

A.
Yasmin decides she can help Will, a junior nurse with very little experience, to be an effective team member.
B.
Megha keeps telling her team members that their chances of doing well against the other teams are very slim.
C.
Ryan tells his junior that looking at his past performance, he is unlikely to do well in his career.
D.
Sofia thinks there is no point in applying for a senior position as she does not have the confidence.
I need help