Simplify \[\frac{4}{7}+0+\frac{-8}{9}+\frac{-13}{7}+\frac{17}{21}\]

• A.  \[\frac{-56}{63}\]                           
• B.                         \[\frac{-86}{63}\]           
• C.                         \[\frac{86}{63}\]                                             
• D.                         \[\frac{56}{63}\]