If (p2 + q2)/(r2 + s2) = (pq)/(rs), then what is the value of (p - q)/(p + q) in terms of r and s?

• A. (r + s)/(r - s)
• B. (r - s)/(r + s)
• C. (r + s)/(rs)
• D. (rs)/(r - s)