If the selling price of 13 articles is equal to the cost price of 14 articles, then _________

• A.  \[gain=7\frac{9}{13}%\]
• B.  \[loss=7\frac{9}{13}%\]
• C.  \[gain=7\frac{1}{7}%\]
• D.  \[loss=7\frac{1}{7}%\]
• E.  None of these