Which of the Following Would Not Motivate a Culture of Optimism

Which of the following would not motivate a culture of optimism within a great team?

A) The team realizing that setbacks become opportunities for improvement.
B) The team encouraging an open dialogue and collaborating to build a compelling vision.
C) The team responding to other's comments with "but . . ." statements rather than "yes, and . . ." statements.
D) The team recognizing what is going well and celebrating their achievements, no matter how small.