\eqalign{ & {\text{Simplify}}\,{\text{if }}\frac{a}{b} = \frac{4}{5}{\text{ and }}\frac{b}{c} = \frac{{15}}{{16}}, \cr & {\text{then }}\frac{{{c^2} - {a^2}}}{{{c^2} + {a^2}}}{\text{ is = ?}} \cr} $$%!

• A. 1/7
• B. 7/25
• C. 3/4
• D. None of these