What is the average of the two middle rational numbers when \[\frac{4}{-9},\frac{-6}{9},\frac{5}{9},\frac{-7}{9},\frac{8}{9}\] and \[\frac{1}{9}\] are arranged in ascending order?

• A.  \[\frac{1}{8}\]                                                  
• B.                         \[\frac{2}{7}\]                  
• C.                         \[\frac{-3}{7}\]                                
• D.                         \[\frac{-1}{6}\]