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

• A. $\frac{1}{7}$$
• B. $\frac{7}{{25}}$$
• C. $\frac{3}{4}$$
• D. one of these