Which One of the Following Statements Should Be AVOIDED in Order

Which one of the following statements should be AVOIDED in order to promote high expectations of your students?

A) "Take your time and try it again."
B) "Good job on the first part of the writing assignment, however, your conclusion paragraph still needs work."
C) "This is easy! Anyone can do it and you can too."
D) "You are right, this is a challenging writing assignment, which is why you need to keep trying."