If a + b + c = 0 then the value of \(\frac{1}{{\left( {a + b} \right)\left( {b + c} \right)}} + \frac{1}{{\left( {b + c} \right)\left( {c + a} \right)}} + \frac{1}{{\left( {c + a} \right)\left( {a + b} \right)}}\) is

• A. 0
• B. 1
• C. 3
• D. 2