If a Child Gets a Terrible Math Grade, Which Statement

If a child gets a terrible math grade, which statement is LEAST effective or helpful?

A) "Let's face it. Some people just aren't born to be good with numbers."
B) "Let's break this challenge into steps, so you can succeed."
C) "Do the best you can. I'll be proud of you if you try very hard."
D) "If you start to lose confidence in your ability to do well in school, think of how well you are doing in Language Arts."