Which of the following are in descending order of their value ?

• A. $\frac{1}{3},\frac{2}{5},\frac{3}{7},\frac{4}{5},\frac{5}{6},\frac{6}{7}$$
• B. $\frac{1}{3},\frac{2}{5},\frac{3}{5},\frac{4}{7},\frac{5}{6},\frac{6}{7}$$
• C. $\frac{1}{3},\frac{2}{5},\frac{3}{5},\frac{4}{6},\frac{5}{7},\frac{6}{7}$$
• D. $\frac{6}{7},\frac{5}{6},\frac{4}{5},\frac{3}{7},\frac{2}{5},\frac{1}{3}$$